Birds In Mud

(Repost) Stubbed Toes and Blood Owies: Footprint Pathologies in Theropod Dinosaurs

Hello, Dear Readers!

Here is another post going into the highlights of one of our more recent papers dealing with dinosaur ichnology: the study of foot injuries in the fossil record!

Have you ever stubbed your toe? Pulled a muscle in your leg? Walked anywhere with a rock in your shoe? It doesn’t take major discomfort to figure out that foot and leg injuries can result in you walking “funny.” Perhaps you had to hop around on one foot for a bit. Maybe you could only take a certain length of step using your injured leg. All of the compensations that you make to avoid further or greater discomfort or pain have a good chance of being seen in your trackway. These modifications due to pelvic limb injuries also have a good chance of being preserved in the fossil record.


Tread Carefully
Of course, we have to be careful when looking at a fossilized trackway and seeing something “odd” about, for example, the gait of an animal. One aspect that can confuse people about vertebrate ichnology is that there is a HUGE amount of variation in how footprints are preserved and in how the animals themselves moved. All of that variation is perfectly normal. Dinosaurs (and any other vertebrate ambling over the landscape) are not metronomes. They are not robots. They will absolutely not take a step that is EXACTLY 345 cm long each and every time they step, or place their feet EXACTLY the same way every time. Some oddities in trackways are just that: oddities that are due to the natural variation in how a living, breathing, complex animal interacts with its environment as it moves from Point A to Point B. 


In other words, when we look for phenomena that we can call pathologies, we are looking for repeated abnormalities in footprint shape and movement. This is the framework we used to review reports of fossilized footprints that preserve oddities that cannot be explained by poor preservation or an animal being an animal.


What Is An Ichnopathology?
When we discuss pathologies, or in this case ichnopathologies, we’re talking about trauma (bone or soft tissue) that would result in an animal walking differently than it would be expected to walk. 
A pathology of the foot would result in direct preservation of the soft tissue and/or skeletal trauma that the foot experienced, such as a dislocated, broken, or amputated toe. A pathology of the lower (tibia and fibula, and muscles) and/or upper leg (femur and muscles) would result in a pace (a footstep) and stride (how the animal moves from right footprint to right footprint, or the “right-left-right” sequence of the trackway) that is different, such as a limp, shuffle, or foot drag, while the footprint itself may (but not always) look completely normal.


What Is Not An Ichnopathology?
There are footprint phenomena that are not ichnopathologies, no matter how strange they may look. Here are a couple of examples.


A. Missing Toes versus Natural Morphology
Here’s the danger of looking at isolated, singleton footprints. Let’s say you see a single footprint with a missing digit II (inner toe). Is this footprint the result of an injury, or is it the footprint of a dromaeosaur? It may be easy to see that the toe is missing, but looking at the trackway is essential in making an accurate interpretation of why that inner toe is “missing”.


Compare these two images:

From Abel, 1935 (McCrea et al. 2015)
Dromaeosauripus yangjingensis, Xing et al. 2012

The top image from Abel (1935) shows a large theropod trackway with a toe missing on only the right footprint. The bottom image from Xing et al. (2012) shows that there is a toe “missing” on both left and right footprints. Both trackways show this as a repeated occurrence. When we see a toe repeatedly missing from one foot only, that is a likely candidate for a pathology. When we see a toe missing repeatedly on both feet, it was likely never there to begin with, as is the case with dromaeosaurs. In fact, a consistently missing digit II is one of the synapomorphy-based characters we can use to confidently identify a trackway as belonging to a member of Paraves.


We have also observed dinosaur trackways where only one footprint shows a missing toe, while all of the other toes are more or less impressed. Those occurrences are most easily explained by preservation, rather than injury or anatomy: not every footprint within a trackway is going to be beautifully preserved.

B. Limping versus Laterality
Remember before when I said that animals aren’t metronomes? It is not uncommon for perfectly healthy animals to favor one limb over the other. This might result in a trackway that looks like it preserves a limp. However, “limping” is a loaded term: it implies that there was an injury or defect that caused the animal to walk the way it does. Data collected from emus (Dromaius novaehollandiae) shows that emus may take longer paces when stepping off with their right foot than if they step off with their left foot (McCrea et al., 2015). In other words, emus are right-handed, or right-footed. Ostriches have also been observed to be a bit right-footed (Bachiodonna et al., 2010). These irregular walking patterns aren’t the cause of injury, but rather because of laterality.

C. Anatomical Anomalies

I have a few bizarre requests for the Universe in terms of cool fossils to be found. One is polydactyly in dinosaurs, or even in a fossil felid trackway. When I was a child my family adopted a polydactyl cat (also known as a Hemmingway cat). Charlie’s hands sported two extra digits each, while his feet each had one extra digit. If Past Me had known Present Me was going to be this much of an ichnology geek, Past Me would have taken pictures of his footprints. No matter how many toes a cat has, there are still features on the foot (and the footprint) that would make it easy to identify it as a cat footprint, like the tri-lobed metatarsophalangeal pad.

FLOOFY TOES! An image of a Maine Coon cat with polydactyly. Although Charlie was not a Maine Coon cat, this is what his forepaws looked like – each extra toe had a functional claw. From mcpolydactyl.com

Polydactyly is not as uncommon as one might think in the fossil record. Early tetrapods, specifically the early amphibians, that first started making their appearance on land in the Carboniferous had more than five fingers and toes on their hands and feet.

Transition of limbs from lobe-finned fish  Eusthenopteron (A, left) to early tetrapods Acanthostega (F) and Tulerpeton (G). Since hands and feet are modified fins, the trend from fin to foot involved digit reduction. By Conty (Own work) [Public domain], via Wikimedia Commons
Figure 4 of Niedzwiedzki et al. (2010), showing a laser scan (left) and a reconstruction of a Middle Devonian footprint from Poland. There may be up to seven digits in this footprint, with superimposed Ichthyostega (middle) and Acanthostega (right) foot.

Let’s fast forward to the Mesozoic. Would we necessarily recognize polydactyly in the footprint of a more derived, specialized tetrapod, like a theropod? There are four-toed footprints that are attributed to theropods. Saurexallopus is interpreted to be the footprint of a theropod with four functional toes. The trackmaker was possibly an oviraptorosaur, such as Chirostenotes (Gierlinski and Lockley, 2013). Having a more well-developed digit I compared to other theropods that were running around at the same time (Late Cretaceous) was normal for Chirostenotes and close relatives, so this is a case of anatomy rather than polydactyly.

3D digital model of Saurexallopus cordata (McCrea et al., 2014) from the Late Cretaceous (early Maastrichtian) Peace Region of British Columbia, like other ichnospecies of Saurexallopus, has a well-developed digit I that impresses with the rest of the weight-bearing toes (digits II, III, and IV).

There are other trackway phenomena that can give the appearance of polydactyly. One of these is a really busy track surface. Busy track surfaces often show animals walking over the footprints of other animals. This often results in dinosaur (and bird) footprints that have the appearance of extra toes, when the simplest explanation is that the footprint is actually one footprint stepping on a different footprint. Another example is when a theropod (usually three-toed) sinks into a substrate deep enough that the hallux and the metatarsus will impress – it gives the appearance of a theropod print with “extra” toes. We see this at the Flatbed Creek Dinosaur Track Site in northeastern British Columbia, where these theropod footprints look like they have five toes instead of the usual three. One toe is indeed a toe – digit I (equivalent to our big toe) – but we don’t usually see that in non-avian theropod footprints. The other “toe” is the impression of the tarsometatarsus.

Flatbed Creek Dinosaur Tracksite, showing two theropod footprints that sunk into the wet, organic-rich ground deep enough to impress the hallux and the metatarsus (from McCrea et al. 2015). Bonus quiz: are these left and right footprints?

I think that if true polydactyly is to be recognized in theropod footprints, it will have to be in a footprint type that is well-studied and found in many different places, like Eubrontes. This is assuming that archosaurs (crocodiles, dinosaurs, birds) have high enough occurrences of a congenital anomoly like polydactyly in natural populations (in crocodiles it may be related to incubation at extreme temperatures – Google Books link). Polydactyly has also been documented in wild birds: follow this link for a report of polydactyly in a Domestic Pigeon.

Now For the Painful Stuff

You’ve seen some examples of what are not ichnopathologies. Now you get to be rewarded with the really painful-looking footprints and trackways…the ones that you look at and cringe because there is no way those injuries were not extremely uncomfortable. Here I will show the recent additions to the owie-ichnology literature. All of our examples come from non-avian theropods. Much like our modern hawks and eagles, Cretaceous theropods likely used their feet for much more than walking: the feet were also a means of prey capture and restraint (Tanke and Currie, 2000). Theropods led hard, fast lives, and that wear-and-tear showed up on their feet.

Those Cretaceous boots were made for gripping, tearing, and ripping all over you.

Despite all that foot use, wild modern birds of prey have a low occurrence of foot injuries: Bedrosian and St. Pierre (2007) documented a 14% pelvic limb injury rate in Red-tailed Hawks and American Kestrels. Like our modern birds of prey, foot-related injuries are not common in non-avian theropods. The percentage of injured theropod feet is small: Rothschild et al. (2001) observed that healed stress fractures in foot elements range from 0.3% to 6% in large theropods. Other injuries to theropod feet include bony growths that likely resulted from infection/osteomyelitis. So, as these injuries are uncommon in theropod foot bones, we can extrapolate that the resulting footprints from injured feet are uncommon. When we see an ichnopathology, we’re lucky (the trackmaker, however, was less fortunate).


1. Trackway Ichnopathology

A trackway of a large theropod (cf. Irenesauripus mclearni) from the Early Cretaceous Gates Formation was reported to us. At first, we thought it might be one theropod following right behind another theropod because the steps the animal was taking were WAY too short.

Pigeon-Toed Waddling Gait in Irenesauripus mclearni, Early Cretaceous Gates Formation. McCrea et al. (2015).

We looked at the substate: it was firm when the animal walked on it, so it wasn’t simply having a tough time slogging through the muck. Then we noticed that the right foot was turned in much more than we usually see in large theropods: non-avian theropods tend to walk with their middle toes pointed roughly straight ahead, or in parallel with the trackway. This theropod was waddling. More specifically, this theropod was using a Pigeon-toed Waddling Gait. It’s hard to say if this gait was the result of an injury to the foot or leg, or if this was a developmental anomaly.

2. Swellings and Dislocations

The most “showy” injuries are those that involve swelling and/or dislocation of a toe. Theropods had no way to reset a dislocated toe, so it would have to walk around with that injury.

Here is a dislocation and swelling-related ichnopathology from the Dakota Group (late Early to early Late Cretaceous) in Colorado.


OUCH! From McCrea et al. (2015)

The second most striking dislocation injury I’ve ever seen in a footprint is this large theropod footprint from the Late Cretaceous (approximately 97 million years ago) Kaskapau Formation in northeast British Columbia. Not only is the middle toe (digit III) severely dislocated, but the outer two toes have seemed to compensate for this injury by spreading way out. Unfortunately, the Kaskapau and the Dakota Group pathological footprints were found as singletons. The good news is that, if these animals’ footprints are preserved elsewhere, we have a good chance of linking the footprints to their trackmakers.

Kaskapau Formation large theropod footprint, which we call “Broken Toe” among ourselves. McCrea et al. (2015)

Footprint swellings like these are also seen in modern birds. Here is a Canada Goose trackway that I collected a couple of years ago. At the time I made the replica, the toe swelling was hidden by the muddy sediment, but it came out beautifully in the plaster replica.

Canada Goose trackway with a noticeable swelling on the outer toe (digit IV). From McCrea et al. (2015)

As painful as these two footprints look, they were a mere inconvenience compared to what this next trackmaker must have suffered. Check out this large theropod footprint (first reported by coauthor Darren Tanke) from the Late Cretaceous Wapiti Formation in northwest Alberta.

Unfortunately, this isolated footprint was lost in a landslide before it could be recovered. (McCrea et al. 2015) 

Yes, you are seeing that correctly: the animal, likely a tyrannosaur (based on the size, and shape of the toe claw, or ungual) stepped on its own toe. Check out how narrow the impression is right before the claw. This could be a trick of the preservation, or it could be that the tissue around the claw was necrotic and beginning to atrophy – this leads to the next level of ichnopathology, also related to tyrannosaurs.

3. Amputations

In 2011 a large theropod trackway consisting of three footprints was reported to us from the B.C. Wapiti Formation. On documenting the trackway, we noticed something peculiar: the inner toe on the left footprints was far too short, while the inner toe on the right footprint was a normal length. Not only did we have the first tyrannosaur trackway preserved, we had one with a rather nasty pathology – a missing toe!

Bellatoripes fredlundi, the first documented tyrannosaur trackway from the Late Cretaceous Wapiti Formation. There were two other trackways made by the same type of trackmaker, as well as a non-pathological footprint (the middle one), which made it possible to name this track type. Naming critters or their footprints based on pathologic specimens is a big no-no. Figure from McCrea et al. (2014)

An Ichnopathology Pain Scale

Everyone is familiar with the pain scale used in hospitals. Hospitals are like not allowed to use my favorite pain scale, courtesy of Hyperbole and a Half. Both these pain scales and all of these foot injuries made me ask “What would a theropod pain scale look like?”

So I dusted off my pencils, Googled horrible foot injuries in animals (there are things that I can’t unsee), and used the Bellatoripes fredlundi trackway and all of those horrible swellings and dislocations as inspiration for The Theropod Pain Scale.

Yup, I made this and it now occurs in the official scientific literature, and I have no regrets or apologies!

There are two reasons I am immensely proud of this image. First, looking at it made all of my staff simultaneously laugh and cringe in empathy pain for the poor afflicted theropod: apparently the lip quiver did them in (yes, I know the presence of lips is debated in archosaurs – the image was meant to have a touch of comedy in it). Second, it was published! The coauthors liked it, but that didn’t guarantee that the reviewers or the editor would have liked it. I’m glad they did – I do my best teaching and interpretation with humor.

The study of ichnopathologies, just like the study of tracks and traces, gives us a closer look at the complex biological lives of these now-extinct large theropods. Fossilized evidence of injuries reminds us of the fragility and vulnerability of animals often portrayed to the public as rough, tough, indestructible eating machines. Even the most fearsome predator has off days and oopsies. Ichnopathology research also demands that we make use of our living laboratory – outside – as an opportunity to look more closely at the common animal trackways we might take for granted. Each one is an opportunity to learn how an animal’s life is reflected in its footprints.

Owie and Ouchie References

Main paper: McCrea RT, Tanke DH, Buckley LG, Lockley MG,Farlow JO, Xing L, Matthews NA, Helm CW, Pemberton SG, Breithaupt BH (2015) Vertebrate ichnopathology: pathologies inferred from dinosaur tracks and trackways from the Mesozoic, Ichnos, 22:3-4, 235-260

Abel O (1935) Vorzeitliche lebensspuren. Gustav Fisher, Jena.

Baciodonna L, Zucca P, Tommasi L (2010) Posture in ovo as a precursor of footedness in ostriches (Struthio camelus). Behavioural Processes, 83, 130–133.

Bedrosian BE, St. Pierre AM (2007) Frequency of injuries in three raptor species wintering in northeastern Arkansas. Wilson Journal of Ornithology, 119(2), 296–298.

Gierlinski G, Lockley MG (2013) A trackmaker for Saurexallopus: ichnological evidence for oviraptosaurian tracks from the Upper Cretaceous of western North America, p. 526-529 in Titus AL, Loewen MA (eds.) A the top of the Grand Staircase: the Late Cretaceous of southern Utah. Indiana University Press.

McCrea RT, Buckley LG, Farlow JO, Lockley MG, Currie PJ, Matthews NA, et al. (2014) A ‘terror of tyrannosaurs’: the first trackways of tyrannosaurids and evidence of gregariousness and pathology in Tyrannosauridae. PLoS ONE 9(7): e103613. doi:10.1371/journal.pone.0103613

Niedzwiedzki G, Szrek P, Narkiewicz K, Narkiewicz M, Ahlberg PE (2010) Tetrapod trackways from the early Middle Devonian period of Poland. Nature 463: doi:10.1038/nature08623

Rothschild BM, Tanke DH, Ford TL (2001) Theropod stress fractures and avulsions as a clue to activity, p. 331–336 in Tanke DH, Carpenter K (eds.). Mesozoic vertebrate life: new research inspired by the paleontology of Philip J. Currie. University of Indiana Press.

Tanke DH, Currie PJ (2000) Head-biting in theropods: paleopathological evidence, in Perez-Moreno BP, Holtz Jr., T, Sanz JL, Moratalla J (eds.). Aspects of theropod paleobiology. Gaia, 15:167–184.

Xing L, Li D, Harris JD, Bell PR, Azuma Y, Fujita M, Lee Y−N, Currie PJ (2013) A new deinonychosaurian track from the Lower Cretaceous Hekou Group, Gansu Province, China. Acta Palaeontologica Polonica 58(4), 723–730.

Field Gal Gear

Packity-Pack! (Don’t Use A Cheap Pack!)

If you weren’t exposed to, or didn’t have the opportunity to experience – outdoor activities, it can be a steep learning journey to find out what works and what doesn’t. I didn’t grow up in an outdoor-gear family. We spent A LOT of time outside, but that was because I grew up in a rural area. We didn’t go on camping trips or epic hikes that required specialized gear. When I started doing palaeontology work in 1997, about 23 years ago…

…is it really 23 years? My calendar must be incorrect. The 90s were only ten years ago, right? RIGHT?!?

Anyway, when I started doing field work AN UNSPECIFIED NUMBER of years ago, my first ever field backpack was a Coleman insulated day pack that my family gave me for Christmas. It was a great idea: they wanted me to be able to keep my lunch cool in the badlands of Alberta.

  1. My Very First Outdoor Backpack

Here’s an image of a Coleman backpack cooler. My circa 1997 pack did not have hip/waist straps, bottle holder, gear webbing, or multiple pockets: it claimed to be nothing more than it was, which was a cooler with backpack straps.

Backpack cooler

It worked! The field work was a series of day trips. We returned to the base station each night, and we never had to hike several kilometers to anything. The pack did its job, and I used it until it fell apart in 1999. By the time I started doing field work in Montana during my undergraduate degree, I needed a new pack.

  1. My Budget Backpacks

I was on a VERY TIGHT budget during my undergraduate studies. Example: I tried to keep my meal costs below $5 per day. I ate A LOT of Campbell’s Tomato Soup and oatmeal (not mixed together: I’m not a monster). I added Ramen noodles to the soup when I wanted something fancy. My idea of eating out was 99 cent bean burrito night at Taco Bell. I was not going to throw serious money at a serious backpack. I went with the $30 book bags at the university book store because it was what I could afford at that moment.

Book bag

Here’s an example of a book bag backpack, the MEC Process Bookbag. Budget-friendly and roomy enough for your electronics and books, it’s great at what it is designed to do, which is to carry your electronics and books. That’s it. Notice the lack of waist straps? It is NOT meant for an expedition-length outdoor survey. Expecting a book bag to do more than a book bag does is unfair in terms of a performance review.

I made my book bags work. I crammed those packs full of everything I needed for a full day of excavating and several kilometer surveys. I NEVER connected my neck, shoulders and back pain with the design of my pack. I just thought it meant that I wasn’t tough enough. If I kept at it, I would toughen up, right? Was I ever wrong!

I didn’t know any better. I didn’t know there were actual expedition packs that are designed to take the weight off of your shoulders and transfer it to the main load-bearing parts of your body: your hips and legs. It’s why you always hear “Lift with your legs, not your back!”

Between 1999 and 2003, I blew through five book bags in five years. At a minimum of $30 per bag, I spent $150 (likely more) on backpacks. Had I known; I could have dropped that coin on one bag that would last me several years. Had I known. You end up spending MORE money on cheap gear over time than you will investing in a pack. If you’re cash-strapped, you have no choice: you just don’t have $150 or more laying around. It’s bloody expensive to be poor.

  1. My First Serious Big-Girl Backpack

In 2003 I switched projects. My new colleague took one look at what I was using for a backpack and said “Dear God, that’s not your pack, is it? Nope, we’re going shopping tomorrow!”

That was my first-ever trip to an outdoor gear store, Mountain Equipment Co-Op.

There were three key features my colleague educated me on:

  1. PADDED WAIST STRAPS. These are they key feature that helps you carry the weight of your pack on your hips (as long as your pack is sized properly.)
  2. PACK FRAME. Does your pack hold its shape, especially the part that rests right against your back? This is super important for keeping the contents of your pack from digging into your back, because the frame holds the gear slightly away from your resting directly on your spine.
  3. HOW DOES IT FEEL? Any respectable outdoor store will help you size your pack and let you test it out in-store under weight. They have sandbags that you can load into your pack and take it on a jaunt around the store. If the store has an outdoor footwear section (they usually do), they should also have a sloped ramp you can walk on. That will give you a good feel for how your pack handles when you’re going uphill or downhill (it matters!)

This MEC Forge 40 Backpack is similar to the day pack I purchased seventeen years ago on super-duper clearance sale. It’s still one of my active day packs.

Day pack

I was in backpack heaven! What a difference a pack with waist straps and a frame made! Although we were only doing day expeditions, at the end of the day we had to hike fossil samples up a fairly steep hill. We started off calling it The Hill of Pain. By the end of the field season we were so used to the hill that we renamed it the Hill of Mild Discomfort. I had much more painful hills in my future.

  1. My First Expedition Backpack

I was soon doing in surveys and expeditions that required hiking with a load of camping gear, tools, and recovered fossil samples. Fossils and gear are heavy!

This requires an expedition pack. I bought my very first expedition backpack in 2004: the MEC Brio 60 (no longer available).

brio70

I love this pack! I STILL use it! It keeps coming back for more, even after all of the horrid abuse I have inflicted upon the fabric of its soul. It was on sale for $99 when I bought it. It is very simple in its design. The features that I love:

  • Generously padded waist straps
  • Removable pack frame (it’s a little tricky to get back in place)
  • Simple interior partitioning
  • Side access zipper for the main compartment
  • Removable top lid with built-in waist straps

The Brio 60 is not a light pack when its empty because of the pack frame, but that frame is essential. We only had to carry fossils from their discovery site to a cache for helicopter pick-up, but first we had to CARRY them to the cache. The heaviest fossil I put in my pack was over 70 lbs. My colleague hauled a dinosaur thigh bone in his bag that weighed over 180 lbs over a three-kilometer trail (not recommended: he was looking a little green at the end of that haul). These packs get the job done.

  1. My First Expedition Backpack Designed for Women

I had tiny issues with the Brio 60. I felt a decent amount of my pack’s weight on my shoulders no matter how I adjusted the waist and shoulder straps. You’re never going to avoid carrying some of your pack’s weight on your shoulders. There are newer backpack designs that do this better, and backpacks designed for women have this as a main feature.

I took advantage of a backpack sale and bought a Gregory Deva 60. I went all in and used this pack for the first time on a 5-day hike-in fossil survey. I was not disappointed!

Gregory

The compartments make sense! There is a roomy main compartment with the option of partitioning off a smaller lower compartment for a sleeping pad and bag. There are two roomy side pockets, and a deep front pocket which I used for storing my on-the-go snacks and the resulting snack trash (pack it in, pack it out!) The top pocket fits snugly over the main opening whether the pack is full or empty. The pack is also designed to use a 3- liter hydration system (purchased separately).

The best features are the lightweight pack frame, structured shoulder straps, and padded waist straps.

My pack had a lot in it! An Outdoor Research Alpine Bivy, sleeping bag liner, sleeping bag overbag, a couple of changes of thermal leggings and shirts, several pairs of wool socks (always wool socks!) rain jacket, three liters of water (we also packed in a water purification system because we knew that water would be available on site), food for five days (including a small bottle of homemade mead), field book, GPS, bottles of glue, digital camera, hiking pole, rock hammer, first aid kit, rain jacket, pack rain cover…I had to live out of this pack for five days.

My pack was still heavy, but it felt good. There was literally a weight being lifted from my shoulders!

What is your favorite large backpack? Do you have an old trusty pack that just won’t quit? Do you have backpack horror stories? I want to hear them!

Birds In Mud

Owls, Part 3: Giant Fossil Owls and Chickcharney

Hello Dear Readers!

We all know that Twitter can be somewhat of a cesspool of ‘splainers, sealions, and a haven for creeps in your DMs.

Twitter has also been a great place to connect with (good) people and share (good) information! I re-shared my previous post about Stolas and the Giant Cuban Owl Ornimegalonyx for International Owl Awareness Day. I was officially today years old when I learned about a legend of a giant owl and a giant extinct flightless owl.

Since I’m a big fan of big owls (and a big fan of small owls…and a fan of all owls, really) we’re going to run with the “giant flightless owl fossil and mythology” theme and talk about Chickcharney and the extinct flightless owl Tyto pollens, also known as the Andros Island barn owl, Bahamian barn owl, or Chickcharney.

Chickcharney, The Legend

Chickcharney (or Chickcharnee/Chickcharnie) calls the pine and hardwood forests of Andros Island, the largest island in the archipelago of the Bahamain Islands. Descriptions of Chickcharnies (there are more than one) tell of feathered bipedal creatures with a prehensile tail, three toes of each foot, and three visible fingers on each hand. Their red eyes are set in heads that can turn completely around. Around one meter tall, Chichcharnies are tree-nesters: if you see a tall pine tree with a fork at the top, that’s where the Chickcharnies will raise their young.

Chickcharney 1
Artistic rendition of Chickcharney, from https://aminoapps.com/c/mythfolklore/page/blog/chickcharney-caribbean-folklore/jxdJ_wEuKu8ZbR4RPDa25j6Q81JYdkPJqJ

If you should happen to visit Andros Island and enjoy a hike in the forests, you would be best to carry a bright piece of cloth or flowers with you: this is said to charm the Chickcharnies. It is also best that one keeps a civil tongue in their head when they encounter a Chickcharney: they are neither “evil” (like the demon Stolas) or “good.” Chickcharnies are known mischief-makers. If you’re respectful to the Chickcharnies, you will have blessings and good fortune. Disrespect Chickcharnies at your peril, however: a lifetime of misery may follow. That may have been good advice for one former British Prime Minister to have followed, according to Chickcharney lore.

Chickcharney
Chickcharney from Cryptid Wiki.

Chickcharney and Neville Chamberlain

Neville Chamberlain was Prime Minister from May 1937 – May 1940, during the first eight months of the Second World War. Chamberlain is more well-known for the Munich Agreement of 1938 (the agreement that ceded western Czechoslovakia to Nazi Germany to appease Adolf Hitler) than he is for his involvement with Chickcharnies, but he does make an appearance in Chickcharney lore.

When Chamberlain was around 20 years old, his father apprenticed him to an accounting firm where he later became a full employee. Joseph Chamberlain saw his family’s fortune declining, so in 1890 he put Neville in charge of establishing and managing a sisal plantation on Andros Island. Sisal, or Agave sisalana, is a species of agave that is originally from southern Mexico but has been cultivated in many places around the world for its stiff hemp-like fibers.

Plantsisal
Agave sisalana, the documented reason of the failure of Neville Chamberlain’s plantation on Andros Island. Sisal did not thrive on Andros Island, costing the Chamberlain family £4.2 million (adjusted).

In 1891 Chamberlain took out a lease on a 110 km square parcel of land on Andros Island for the venture. This was possible, of course, because Great Britain began colonizing Andros Island in 1783, complete with all that entails (a.k.a. slavery.) Great Britain wasn’t the first nation to colonize and exploit Andros Island. Prior to the arrival of Spanish colonists after the initial invasion of the island between 1499 – 1500, the Lukku-Cairi people lived on Andros. Thanks to the exploitation of the Lukku-Cairi people, by 1520 the population was considered extinct.

Chamberlain spent six years trying to make the plantation work. His efforts failed. The official story is that Agave sisalana did not grow well on Andros Island. That’s too bad for Chamberlain, because the failed plantation cost the family business a whopping £50,000 (or £4.2 million in today’s dollars). [Cue sad slide-whistle noise.]

What does this have to do with Chickcharney, you ask? Well, legend has it that during his ill-fated stay on Andros Island, Chamberlain openly scoffed at the stories of the Chickcharney (as European colonizers are wont to do at the legends and lore of the areas they colonize.) The Chickcharnies apparently did not take kindly to be openly laughed at. Despite the official story of sisal’s incompatibility with the area, the failure of the sisal plantation is credited to the intervention of the offended Chickcharnies. A nod is also given to the Chickcharnies for another event that will be forever linked to Chamberlain’s legacy: the Munich Agreement ultimately failed as it did not halt the invasion of the rest of Czechoslovakia by Nazi Germany as was hoped.

Don’t laugh at owls, my friends. Or legends/folklore of critters that resemble owls. It just isn’t worth the risk.

Tyto pollens, the Bahamian Owl

As we saw in the last OWLS! post about the Cuban Giant Owl Ornimegalonyx (Late Pleistocene: 126,000 – 11,700 years ago) and Stolas, the demon character from Collin de Plancy’s Dictionnaire Infernal, are likely a case of wonderful coincidence rather than the knowledge of the fossil influencing the art/mythology. However, that may not be the case for Chickcharney and its Quaternary doppelganger, Tyto pollens.

Tyto pollens, also known as the Andros Island Barn Owl, Bahamian Barn Owl, Bahamian Great Owl, and – not surprisingly – Chickcharney, is a recently extinct owl that is in the same genus as the Barn Owl. The Andros Island Barn Owl is estimated to have stood at one meter (three feet) tall, and was considered by Wetmore (1937) as much more robust and stronger than the Barn Owl. Tyto pollens, like all owls, was a predator. What does a 1 meter tall owl eat? Wetmore (1937) thought that Tyto pollens likely preyed on the large rodent Geocapromys.

Tyto pollens femur
Part of the type specimen of Tyto pollens (USNM PAL 283287), the femur (Wetmore 1937).

OLYMPUS DIGITAL CAMERA
Geocapromys, a large rodent endemic to the Bahamas and Jamaica that was likely prey for Tyto pollens. Museum of Comparative Zoology, Harvard University 

Tyto pollens is younger than the Cuban Giant Owl Ornimegalonyx in that it was present in the old growth pine forests of the Quaternary. This means that Tyto pollens was most likely seen by the original population of Andros Island: the Lukku-Cairi people most certainly encountered a 1 meter tall flightless owl. The owl was reported to have still been present on the island during the colonization by the Spanish and the British, so it is likely that any sightings of the Andros Island Barn Owl by the colonizers of Andros Island would have only served to strengthen the lore of Chickcharney. It was once the old-growth pineyards were deforested that Tyto pollens lost its habitat and went extinct in the 1600s.

Tyto pollens is noted to be very similar to another fossil owl, Tyto ostologa (Wetmore 1922) from cave deposits in the Republic of Haiti. Tyto pollens is reported to be larger than the Quaternary-aged Tyto ostologa. This is what I find the most fascinating about the story of Chickcharney: giant owls were not an isolated phenomenon. 

Tyto ostologa
Type specimen of Tyto ostologa (USNM 10746), the top of the tarsometatarsus (Wetmore 1922).

The likelihood that Tyto pollens (and also Tyto ostologa) had inspired and influenced the lore of the Chickcharney is fairly high: the timing is right for the geographical and temporal ranges of T. pollens and humans to overlap. However, I really want to know for sure. The next step in investigating the Andros Island Barn Owl is to check documents written during the time period that Tyto pollens was still with us (a.k.a. extant) to see if there was any direct mention of a sighting of a giant owl or of a Chickcharney. I’ll be excited to see what turns up!

References:

Bahamian Folklore: https://web.archive.org/web/20070828074515/http://bahamian.dynamohosting.net/bol/index.php?option=com_jd-wiki&Itemid=98&id=wiki%3Abahamian_folklore

https://itsmth.fandom.com/wiki/Chickcharnee

Tyto pollens:

Wetmore A. 1922. Remains of bird from the caves in the Republic of Haiti. Smithsonian Miscellaneous Collections 74(4): 1-6.

Wetmore A. 1937. Bird remains from cave deposits on Great Exuma Island in the Bahamas. Bulletin of the Museum of Comparative Zoology 80(12): 1-7.

Marcot BG. 1995. Owls of the old forests of the world. General Technical Reports. Portland, Oregon. U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, 1-72.

Birds In Mud

Owls, Part 2: Giant Fossil Owls and Stolas

It’s time for the next installment of my OWLS! series of blog posts! This one is going to be a little bit different from my other posts…although, if you’ve read any of my Bigfoot or ghost posts you may not be surprised at the theme of this post.

My research takes me down a few interesting rabbit holes. One of these holes introduced me to J. A. S. Collin de Plancy’s Dictionnaire Infernal when I searched for “giant owls.” I was looking at adaptations that cursorial (ground-running or walking) birds have in the tarsometarsus bones. That is where I encountered Stolas.

Stolas is my favorite (is favorite the right word?) character of Collin de Plancy’s demon mythology from the perspective of both an owl fanatic and a palaeontologist. Collin de Plancy describes Stolas on page 635-6 of the Dictionnaire Infernal:

“Stolas, grand prince des enfers, qui apparaît sous la forme d’un hibou ; lorsqu’il prend celle d’un homme et qu’il’se montre devant l’exorciste, il enseigne : l’astronomie, ainsi que les propriétés des plantes et la valeur des pierres -précieuses. Vingt-six légions leire connaissent pour[;] general.”

Here is my extremely rusty high school French (with a double-check in Google Translate) translation:

“Stolas, great prince of Hell, who appears in the form of an owl; when he takes that of a man and shows [himself?] before the exorcist, he teaches astronomy, as well as the properties of plants and the values of precious stones. Known for Twenty-six legions; general.”

Stolos
Stolas: “Go ahead: run. I dare you.” Image from Collin de Plancy, Dictionnaire Infernal.

If Stolas were real, he’d likely be a great resource of information for many in astronomy, botany, and geology. The geology link of Stolas is what makes the connection of Stolas to paleontology even more interesting. As a field palaeontologist I would find a twenty-six-legion strong field crew very useful.

Most of the demonic entities in the Dictionnaire Infernal (and earlier works on the same subject) appear as human-animal hybrids or large versions of familiar animals. Collin de Plancy does not give us a sense of scale but one’s brain does jump to “large,” or at least larger than life, when talking about demons. The dimensions of Stolas are fascinating: the woodcuts of Collin de Plancy show an owl with rather long legs, standing on the ground. The legs are longer than the body. There’s a lot going on with the appearance of Stolas that suggests he is a walker. It is unlikely that Stolas’ teeny owl body with those teeny owl wings and itty-bitty tail could haul around those legs during flight (especially while wearing his resplendent crown.)

Bestiaries and Owls

Owls appear frequently in the medieval literature, particularly in bestiaries. Bestiaries (no, not bestiality, although the root of both words is the same) depict animals both real and fanciful, from the Amphisbaena (a serpent with a head at either end), to odd interpretations of real animals. Did you know the Barnacle Goose grows from trees, dangling from their beaks? According to the Harley Bestiary (c. 1230-1240), that’s where Barnacle Geese come from!

Barnacle Goose img4465
British Library, Harley MS 4751, Folio 36r

Or how about bees: did you know that bees come from the decay of the putrid flesh of calves or oxen (Isidore of Seville, 7th century CE)? Some explanations are implausible, others are darn ridiculous, but they were interpretations based on observations made at the time. The prevailing wisdom of the day, according to the bestiaries, was that owls were dirty, slothful birds that pollute their nests with their own dung. Barn owls do build up a layer of pellets in their nests when the young are still in house and feeding, but most birds are pretty good at keeping waste out of their nests. It was common knowledge that owls frequent graveyards and tombs, and their cries are harbingers of an impending death. It’s not a glowing letter of recommendation.

Owls and their portrayal in bestiaries is a whole other post, but these bestiaries were written in the 12th – 16th centuries. Bestiaries were not immune to the prevailing attitudes of the day. Some of these ideas were, well, racist and antisemitic as flock. With the negative interpretations associated with owls, it makes sense that someone with an interest in both the natural and the spiritual world would have a demon appear as a larger-than-life owl, ready to run you down if you lost your nerve during a demon summoning. We can safely say that Collin de Plancy and Friends didn’t actually summon Stolas (or any demon) to pose for a sketch artist. We can chalk up mystic depictions of demonic giant walking owls as a stroll down Imagination and Theology Lane.

The Giant Cuban Owl

Fast forward to Cuba, 1954, where we actually have knowledge of a giant owl. The Cuban Giant Owl Ornimegalonyx was an owl of the Late Pleistocene (126,000 – 11,700 years ago, also known as the Ice Age). Ornimegalonyx was discovered on January 2, 1954 and was recognized as the remains of a large predatory bird. The discovery site was a large cavern called Pio Domingo Cave located in the Sierra de Sumidero, opposite Pica-Pica Valley in Pinar del Rio. Ornimegalonyx was originally described by Oscar Arrendondo (1958) in a publication called El Cartero Cubano. Oscar Arrendondo originally used Ornimegalonyx arrendondoi as a provisional name, and he later uses Ornimegalonyx oteroi as the official name in his 1958 publication describing the type specimen. Arrendondo used the name “oteri” in honor of speleologist (scientists who study caves) and expedition member Juan N. Otero (Arrendondo, 1958). The type material (the bones that everyone has to look at if you want to work on fossilized giant owls) consists of a fragmentary femur (thigh bone), three fragments of a tibiotarsus (shin bone), an incomplete tarsometatarsus (the lower part of the “backwards-looking-knee” of a bird – it’s the same as our ankle), and some toe bones (phalanges).

Cuban Owl legs
Image of leg bones from Ornimegalonyx (Arrendondo 1976)

Original descriptions of Ornimegalonyx have it belonging to the group Phorusrhacidae (also known as “terror birds”) because of the large size. Back in 1958, large owls were not on people’s radar. This small collection of bone fragments doesn’t sound like a lot on which to base the naming of a new critter, but there are parts of owl leg and foot bones that are Classic Owl. Ornimegalonyx was estimated to have stood about 1.1 m (3’7”) tall and likely weighed around 9 kg (20 lbs).

ornimegalonyx
The best Ornimegalonyx image ever. Twilight Beasts introduced me to this image (link here) and blog where this and other great images come from (link here). Check out the Terror Bird image when you visit (because of course you’re going to visit the site)!

As owls go, Ornimegalonyx (orni = bird; mega = large) lives up to its name. Let’s look at its size in comparison to a fairly well-known and our largest owl alive today, the Eurasian Eagle-owl (Bubo bubo). The leg bones, the femur (thigh bone) plus the tibia (shin bone) plus the metatarsals of an Eurasian Eagle-owl are 10.8 cm, 15.5 cm, and 8.4 cm, respectively. We can estimate the leg length of the Eurasian Eagle-owl (give or take some soft tissue and cartilage) at 34.7 cm (or about 13.6 inches) long. The leg bones of Ornimegalonyx are 15.4 cm, 25.0 cm, and 14.7 cm. The estimated leg length of Ornimegalonyx is 55.1 cm (or 21.7 inches). This is how Arrendondo estimated the height of Ornimegalonyx at about 1.1 meters (3`7”)! Compare that to the height of the Eurasian Eagle-owl at 75 centimeters (around 30 inches). That’s a big owl! Most artistic reconstruction of Ornimegalonyx show a critter similar in shape to a Burrowing Owl (Athene cunicularia) due to the long legs and the interpretation that Ornimegalonyx spent more time running and walking than flying.

Was Ornimegalonyx unable to fly like our present-day owls? That’s an interesting question that’s still being examined. It’s definitely not the overall size of Ornimegalonyx that would have kept it grounded. The Secretarybird (Sagittarius serpentarius) is slightly taller than Ornimegalonyx at about 1.3 meters (4.3 feet tall). It is not even the estimated weight of Ornimegalonyx (uncited at around 9 kilograms) that would have made flying untenable: the Andean Condor weighs in at 15 kilograms.

Ornimegalonyx was not taller than a Secretarybird or heavier than an Andean Condor. Ornimegalonyx may have not been a “feathery death from above” kind of owl, but more of an “I will run you down” owl. Arrendondo (1976) states that the sternum (that’s the breastbone) doesn’t have a large enough keel (the bony projection in the middle of the breastbone) to hold the chest muscles required for a flying bird. Think of carving up the white meat of a turkey breast during the holidays: those are the flapping muscles of the downstroke of the wings, the pectoralis major and pectoralis minor. There’s enough of the sternum preserved of Ornimegalonyx to make a decent reconstruction.

Cuban owl sternum
Sternum and keel of Ornimegalonyx (Arrendondo 1976).

The keel of Ornimegalonyx is not as large as that of a Burrowing Owl or of the similarly-sized Secretarybird. Even vultures have a comparatively larger sternal keel than that of Ornimegalonyx, and vultures are more known for soaring on thermals than for dive-bombing stealthy death from above. Given that Ornimegalonyx didn’t have a lot of room on its breastbone to attach flapping muscles, it likely spent a great deal of time on the ground, terrorizing the Ice Age mammals. However, new specimens and more investigation will shed light on this in the future.

secretary bird
Skeleton of the Secretarybird (similar in size to the Giant Cuban Owl) on the BHL Biodiversity Heritage Library by Eduard d’Alton for his & Christian Heinrich Pander, Die Vergleichende Osteologie (1821-38). Contributed for digitization by Smithsonian Libraries (@silibraries). You can see the keel is pretty deep on the sternum.

Did Ornimegalonyx Inspire the Idea of Stolas?

Would Collin de Plancy have known about Ornimegalonyx, or preserved remains of creatures that would have inspired visions of demons, when he wrote Dictionnaire Infernal (1818; illustrated version in 1863)? We don’t have any reason to assume Collin de Plancy himself had any knowledge of giant fossil owls. As far as I know, there is no documented contact between Collin de Plancy and Cuba (I’m still looking.)

Theological interpretations of the natural world happened at late as the 1800s. Fossilized meat-eating dinosaur (theropod) footprints were described as the footprints of Noah’s Raven by Elihu Dwight as late as the 1800s. Edward Hitchcock later described these same tracks as those belonging to an extinct bird in the 1830s. Scriptural-based interpretations of natural phenomena were still prevalent when the Dictionnaire was written. Heck: these types of explanations for natural phenomena still happen today, so we really can’t side-eye past historians and naturalists too much if they assumed that demons appeared in owl-form.

The likelihood of Collin de Plancy having heard tell of fossils of Ornimegalonyx, or skeletons of a Stolas-like demon from Spanish colonies is possible. Spanish colonization of Cuba began during the 1492 expeditions, and was briefly colonized by Great Britain in 1762. French colonization of Cuba began in the 18th century and increased into the 19th century.  People were aware of fossils during this time. In the 1400s there was recognition that the phenomena that we call fossils were the remains of ancient life. Fossils were even described by Aristotle (348-322 BC) as being once-living organisms that were “petrified.” Unfortunately, I haven’t come across records of pre-1900s discoveries of fossils on Cuba. Columbus was likely aware of amber (http://www.nytimes.com/books/first/p/poinar-amber.html) as amber was used by the indigenous peoples who Columbus viciously exploited on the island of Hispainola. However, it seems unlikely that Columbus would have paid much attention to fossilized animals of Cuba, and there certainly has never been a report of a fossilized giant owl encased in amber.

Just because colonists may not have heard about giant fossil owls doesn’t mean they were unknown. People may have encountered Ornimegalonyx. There are records of people from the Palaeolithic Periods after the Ice Ages (Guanahatabey and Siboney cultures) living in Cuba.

It’s not often we have a real-life version of a mythical character such as Stolas. It doesn’t “prove” that Stolas is the real deal, or that owls represent demons. We still have a lot of work to do to shake off some of the negative associations people have with wildlife. Wolves, bats, owls, ravens, vultures: these are animals that are still associated with hunting, death, night, and evil doings. These animals are not evil: it’s only our associations and biases that interprets them as such. The more we learn about how wonderfully complex our natural world is the easier it will be (I hope) to exorcise the demons of our biases from these misunderstood animals.

References:

Arrendondo 1958. Aves gigantes de nuestro pasado prehistorico: El Cartero Cubano, v. 17, no. 7 (July), p. 10-12, unnumbered text-figs.

Arredondo, Oscar and Olson, Storrs L. 1976. “The great predatory birds of the Pleistocene of Cuba.” in Collected Papers in Avian Paleontology Honoring the 90th Birthday of Alexander Wetmore, 169–187.

Birds In Mud

Owls, Part 1: Fossil Owls

Hello Dear Readers!

Live nest cam season is here (and sadly it is now past: too many major life changes happened that put this blog post on hold)! Nest cams are windows into the wonderful world of a very important time in the lives of our present-day theropods: mate interactions, nesting, brooding, and raising young.

Besides being completely fascinating, watching owls (and hawks, and osprey, and albatross) nest and raise young is that we know that Cretaceous theropods also courted their mates (1), constructed nests, laid eggs, and cared for their young. Here’s a link to an earlier blog post where I cover theropod nesting, brooding, and determining the sex of a theropod: http://birdsinmud.blogspot.com/2017/04/theropods-or-tender-pods-softer-side-of.html  There is a lot that we can learn about the lives of extinct theropods by studying our present day theropods!

Other than the previous blog post on the tender side of theropods where I link to owl nest cams I realized, while watching the Barred Owl snooze in her next box, that I have never written about owls as their own topic.

7fcdfc3045bb2898c9d93fd25784d52e
I think I may have ruffled some feathers on this Barred Owl.

So let’s talk about owls! I want to do a series of blog posts that highlight all that is fascinating about owls – I find everything about owls fascinating, so who knows how many posts this will be!

To start our conversation about owls we have to start at the beginning, which means we’ll be looking at the fossil history of owls!

Owl Features…In Bones

To talk about owls we have to talk about what features make owls what they are. If we don’t know what makes an owl an owl, we can’t figure out when owls first evolved. I’m only going to talk about owls as we recognize them from their skeletons because that’s what we have to work with as palaeontologists.

Owls belong to an order of birds called Strigiformes. This term was first coined by Wagler in 1830. To get into Club Strigiformes, you’d have to have the following characteristics:

  • Large, round, front-facing eyes (can fossilize),
  • Bony ring in the eye socket (sclerotic ring) is a solid, elongate tube (can fossilize),
  • Eyes in a circular or heart-shaped disk of radiating feathers (not skeletal),
  • Relatively large head (can fossilize),
  • Holes in the neck vertebrae where the arteries run through are about 10X the size of the artery (can fossilize),
  • Sharply hooked beaks (can fossilize, but shared with other birds of prey),
  • Hooked talons (can fossilize, but shared with other birds of prey), and
  • Feathers with serrated edges to reduce noise in flight (not skeletal).

Those are very general characteristics of an owl’s body. When we get down to the nitty-gritty of “How do I know my fossil bird is an owl?” we are dealing with parts of a bird skeleton that are more likely to fossilize than others. Skulls, with their thin braincases and thin bony struts, may not fossilize well (but it does happen). Bones that are relatively more sturdy, typically limb bones, have a better chance at fossilizing. This is why many of the oldest owl fossils are just that: limb bones or parts of limb bones. The most common limb bone of fossilized early owls that shows up in the scientific literature is one of my favorite bones, the tarsometatarsus.

Great-horned-owl-Bubo-virginianus-right-tarsometatarsus-posterior-Abel-collection-600x600
Great Horned Owl tarsometatarsus, seen from the back. This is a stout, sturdy set of three fused metatarsals. http://www.boneid.net/product/great-horned-owl-bubo-viginianus-right-tarsometatarsal-posterior-view/

If you picture a bird leg, you are probably familiar with the “backward knee” look that they have. That “backward knee” isn’t the knee at all: that’s the equivalent of our angle joint between the tibiotarsus and the tarsometatarsus. Remember those “if dogs wore pants” memes that circulated a few years ago? Well, if birds (and extinct theropod dinosaurs) wore shoes, they would look something like this:

theropod shoes
This glorious bit of artwork was painstakingly sketched over the course of five minutes using a page from my quasi-bullet journal. Theropods likely wouldn’t want to wear high heels: it would interfere with the “spring” in their step.

The tarsometatarsus is one of my favorite bones in a bird skeleton because there’s a lot of identifying information in the area where the tarsometatarsus connects to the tibia and where the toes connect to the tarsometatarsus. I focused on the tarsometatarsus of shorebirds for my doctoral thesis because I wanted to understand the link between footprint shape and foot bones. [Results in progress.]

One of the obvious features of a bird of prey tarsometatarsus is the huge roller surfaces of the distal end – where the toes attach. Birds of prey are a lot like their extinct meat-eating dinosaur cousins: they do a lot of their prey catching with their feet. Those toes gotta be able to grip it good, so the roller surfaces are nice and robust. Check out the tarsometatarsus of a Bald Eagle.

BAEA-tarsus-12154-back-DSC_4157
Bald Eagle tarsometatarsus. The inner toe (digit II) is LARGE, and the roller surfaces are all in a line. https://royalbcmuseum.bc.ca/Natural_History/Bones/Species-Pages/BAEA.htm

Now, check out the tarsometatarus of a Great Horned Owl! Do you see the one roller surface – the outer roller – that is twisted?

Great-horned-owl-Bubo-virginianus-right-tarsometatarsus-posterior-Abel-collection-600x600

This is a bony feature of a special owl foot trait, called the zygodactyl foot. Check out the feet of the Eurasian Eagle Owl coming in for a landing. Do you see how the outer toe is facing more backward than forwards? That’s a zygodactyl owl foot.

1dbb15d1a780c9b871e99315a7ae4d46

 

Even long-legged owls like the Burrowing Owl have a fourth/outer roller surface that is twisted!

Burrowing_Owl_s52-12-055_l
Burrowing Owl. https://www.audubon.org/field-guide/bird/burrowing-owl

Burrowing Owl TMT.jpg
Burrowing Owl tarsometatarsus from Aves3D. It doesn’t really sit straight because of the fourth distal metatarsal “twist.” https://aves3d.org/public_images/show_image/5654?specimen_element_id=473&specimen_id=152

One feature that diurnal (active in the daytime) predatory birds have is a built-in sun-visor over each eye. This sun-visor is called the supraorbital process. In diurnal birds this ridge can be very pronounced, but in nocturnal birds this visor is smaller. In diurnal owls (Great Horned Owls are an example) the ridge is well-developed!

Skulls unlimited Great Horned Owl skull
Great Horned Owl skull from Skulls Unlimited. See the flange of bone above the round tube of bone? That’s the bony “sun visor.” https://www.skullsunlimited.com/products/replica-great-horned-owl-skull-bc-072

In the Boreal Owl skull, we don’t see that bony sun visor: the edge of the upper eye socket is rounded and smooth. But check out those asymmetrical ear openings! This feature allows sound to come into the owl’s ears at two different levels, giving the owl precision targeting of small furry/feathery/fluttery prey. If you’re hunting at night, you need to pull out all the tricks to get a tasty meal!

Boreal Owl Skull

These are two out of MANY features that make an owl an owl if all you find is the skeleton. That’s what we deal with when we talk about fossil owls.

Fossil Record of Owls: The Wise Oldest Owl

You might find this surprising, but owls have been around for a long time! We don’t yet have any definite owls from the Cretaceous Period, but in the time immediately after the Cretaceous – Paleogene extinction (when non-birdy dinosaurs went extinct 66 million years ago) owls are there! This suggests that owls – or very early versions of owls – may have evolved in the latest Cretaceous Period (2). Why is this? It’s because the “owly” features are fairly well-developed, and bony features take time to evolve in groups of animals.

That’s not to say that people haven’t thought they had evidence of Cretaceous owls. Bradycneme draculae (3) was described by Harrison and Walker in 1975 from the Maastrichtian (70 – 66 million years ago) age deposits of Transylvania (yes, they went there.) Following the description of Bradycneme as a Cretaceous owl, many researchers started to compare the end of the tibia (that’s the shin bone) to bones of theropod dinosaurs. It is very likely that Bradycneme is actually a funky little theropod called an alvarezsaurid (4).

Here’s an image of Patagonychus, an alvarezsaurid. Check out the wee little arms!

220px-Patagonykus
Patagonychus. https://en.wikipedia.org/wiki/Alvarezsauridae

Our first Wise Oldest Owl comes from the lower Paleocene deposits of Colorado, USA (Tiffanian: 60.2 – 56.8 million years ago). Ogygoptynx wetmorei is known as a “protostrigid:” it’s really really close to being an owl it’s scary, and it has features that are seen in both typical owls (like Great Horned Owls) and the Barn Owl kind of owl. Ogygoptynx is known from a tarsometatarsus (5).

Ogypt tmt
Ogygoptynx wetmorei tarsometatarsus. There’s a slight twist in the outer toe roller surface (you can tell the outer tarsometatarsus because of the small hole between metatarsals III and IV). The outer metatarsal roller surface is also slightly separated from the rest of the “bundle” of fused metatarsals (5).

Our next Wise Oldest Owl is Berruornis, which comes from the upper Paleocene deposits (59 – 56 million years ago) of the Reims area of northeast France. Berruornis is known from – surprise! – a nice sturdy tarsometatarsus! One of the owly features of Berruornis is seeing the fourth distal tarsometatarsus – the roller surface – starting to get that zygodactyl twist! Berruornis fossils are also found from the Late Paleocene rocks in Germany.

Berruornis
Tarsometatarsus of Berruornis. If you check out the middle image, you can see the small “twist” in the fourth roller surface as it peeks around the shaft (6).

This kickstarts my blog series on OWLS! The next post will focus on one fossil owl in particular…and this owl has some interesting mythological connections! Stay tuned!

References

1.  Lockley MG, McCrea RT, Buckley LG, Lim JD, Matthews NA, Houck KJ, Gierliński GD, Surmik D, Kim KS, Xing L, Kong DY, Cart K, Martin J, Hadden G. 2016. Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behavior by Cretaceous dinosaurs. Scientific Reports 6, Article number: 18952 (2016)

2. Harrison CJO, Walker CA. 1975. The Bradycnemidae, a new family of owls from the Upper Cretaceous of Romania. Palaeontology 18(3): 563-570.

3. Naish D, Gareth J. 2004. Heptasteornis was no ornithomimid, troodontid, dromaeosaurid or owl: the first alvarezsaurid (Dinosauria: Theropoda) from Europe. Neues Jahrbuch für Geologie und Paläontologie Monatshefte 7: 385-401.

4. Kurochin EN, Dyke GJ. 2011. The first fossil owls (Aves: Strigiformes) from the Paleogene of Asia and a review of the fossil record of Strigiformes. Paleontological Journal 45(4): 445-458.

5. Vickers-Rich P,  Bohaska DJ. 1981. The Ogygoptyngidae, a new family of owls from the Paleocene of North America. Alcheringa 5(2): 95-102.

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