#paleo reconstructions

[datgreenmonstah]

Theropod Facial structure theory

I have been trying to write this paper out so many times and the lack of funds to hire an editor/publish as well as getting this organized in a fashion that's considered proper for a scientific paper has caused me to hit so many walls, not including the learning disabilities that have made this worse to get this out. So i'm doing this to get what information i've been gathering since 2018.

looking at young corvid images of their open mouth, they had a lip area in their mouth that the upper beak would overlap and lay in perfectly, this is what started me down the road along with noticing the formina on the sides of theropod faces matched that of goose skulls I saw online. As I had no access to actual specimens in person.

feeling as though waterfowl specimens were the easiest to obtain(they were actually more difficult than thought) as well as being closer to dinosaurs on the evolutionary tree next to ratites, and even living along dinosaurs during the late cretaceous ie presbyornis, they seemed to be the best to study for this.

After obtaining a pair of peking duck and an african goose, from some local farmers that donated them, they were dissected and preserved using techniques learned from taxidermy for study. The specimens had one side of their bills removed while leaving the skin intact on the otherside. One of the peking ducks kept the tissue on both sides, while only one side had the top layer of the epidermis removed, exposing the harder dermis underneath. A noticeable attribute was that before preservation the bills were plump and didn't show any texturing, except for the goose around the back nearest to the corner of the mouth. Once preserved however, the skin on the bills shrank, revealing grooves and texturing where nerves and blood vessels would run.

The sensory organs and nerves that ran in the bills were observed using a candlelight method/ie holding them up to the light.

Tyrannosaurus Juvenile Jane specimen for comparison

The deep grooves and formina on the bill, as well as the formina and grooves that are seen in T.Rex have many similarities, which was the main focus of this study as they're are numerous studies pertaining to their sensory organs. Also something to compare is that there is a distinct row of formina that's more prominent on older crocodiles and alligators along the dentiary similar to that of T.Rex, on both the top and bottom row of the mandibles.

saltwater crocodile head from crocodiledarwin.com and alligator from encyclopediaofarkansas.net

komodo dragon profile view(comparing formina)

Though waterfowl having lamillae cannot be used to compare enamel ware. While crocodiles and alligators have teeth, but are known for not having lips, have ware and tare on their teeth than animals like monitor lizards that have lips as shown in this study using a relative of Tyrannosaurus rex to prove they had some form of lip to protect their tooth enamel.

Another observation is that in alligators the bottom row of dentary is tucked under the upper mandible and covered more than in crocodilians. It would be interesting to see the tooth study done with other teeth on both animals, as some of the posterior dentary on the upper mandible can sometimes be seen tucking away in a pocket of skin as protection in some alligators.

Also looking at neonatal alligators shows a depression in the lower jaw area that the upper dentary could sit in, almost as though their reminants of lips

neonatal alligator from natgeo on alligator facial mechanoreceptors

and while alligators and crocodilians seem to have scaling on their face this is just thickened sensitive skin with cracked texturing imitating scales. Bills on waterfowl are also thickened as this allows them to forage in merky waters and plants without damaging their bills. While both animals have thickened skin on their manidbles, it is still a very sensitive part of their body that they use to navigate and explore/manipulate their environment as well as interact with other of their species. While reptiles have less sensitivity and do not share these organs along their faces(the skin sense organ of some iguanian lizards). This could be also a lack of information on the anatomy of reptile skulls and facial structures that could be expanded more for comparison.

However there was a study done on the facial sensitivity of Tyrannosaurus along with alligators

See Complex Neurovascular system in the dentary of Tyrannosaurus

See Despite their thick skins, alligators and crocodiles are surprisingly touchy

and while it took awhile to find and make available, there had been a paper written on a very similar organ within the bills of waterfowl, namely mallard ducks.

See The Morphology and Distribution of Cutaneous Mechanoreceptors(Herbst and Grandry Corpuscles in Bill and Tongue of the Mallard)

And while Monitor lizards and other reptiles share a similar formina pattern, they lack the textured grooves and sensitive organs archosaurs and certain avians share, as well as other anatomical features of moniotor lizard skulls that they share more closely with other reptiles and snakes than they do with the archosaurians and avians.

komodo dragon skull ventral view

Alligator(left) Crocodile(right) ventral views of skulls

Peking Duck skull with bill skin(ventral view)

T.Rex skull ventral view

another observation in many reptile skulls is how the upper and lower dentary interact. While some had teeth that overlapped the lower mandible, there seemed to be somewhere that the teeth met, either at the anterior end of the skull or continually all around, in monitors there was some sort of gap at the anterior portion of the dentary to make way for the tongue to be able to slide in and out without being obstructed too much while allowing the mouth to stay closed. Where as archosaurs and avians the two overlapped one another allowing for a scissoring affect with the teeth, the most noticeable being the anterior end of the mandibles. And while waterfowl lack the dentary that archosaurs and reptiles have, the lamillae still slide past one another similar to what's observed in many theropods, even in non avian dinosaurs. The thought of bone to tooth contact is considered as well, and there can be a sizeable closure without the need for the amount of soft tissue observed in reptiles.

proposed crocodilian like contact of tooth on mandible(top), proposed soft tissue similar to that of monitor lizards(bottom left), new proposed soft tissue without scaled lips(bottom right)

Having soft tissued lips that is similar to that of a waterfowls bill allows for the mechanosensory corpusicules to interact as well as still allows for protection of the tooth enamel.

The way their upper dentary line up with their lower mandibular formina seems to follow the same pattern, compared to reptiles that didn't curve upwards towards the anterior portion of the lower mandible. There's also a possibility of having a nail, like waterfowl, or some large scale, like many other reptiles with dentary, at the anterior ends of the upper and lower manible. This is due to the amount of formina clustering in a pattern like structure similarly seen in both waterfowl and reptiles.

These observations and studies allowed for an idea of how to reconstruct Tyrannosaurus Rex

Juvenile Jane Tyannosaurus Rex skull, with open and closed mouth(top) and reconstructions

Even constructing a physical reconstruction to better observe how the lips and teeth would interact.

Paper mache head reconsturction done in a similar manner to the duck and goose specimens used in this study

Also when reconstructing, and also accounting for tooth slippage, there was an issue with a sizable gap at the anterior end with the front dentary when closing the jaws when attempting to imitate the mouth closing similar to that of previous reconstructions using reptile lips, where as with the more waterfowl skin reconstruction there was less of an issue and also less of an overhanging bottom lip.

Pages from personal study notes

There was also the issue of either exposing the jaw muscles similar to how crocodilians, alligators, and other reptiles are observed to have, or to cover it in skin like birds. One of the arguments is that the mouth wouldn't be able to open to the extent allosaurians and tyrannosaurus are able to open their mouths. When there are several avian species with skin over the area that can very well open their mouths just as wide, ie Bell Birds, which have a widened jugal bone like that of tyrannosaurus.

Young tyrannosaurus specimen(chomper)

Also to note, in most reconstructions where there is a bony knob on the jugal, circled in the above example, is more than likely a muscle attachment point, and the divet in the space before the attachment point could allow for the corner of the lips to sit.

In conclusion, Tyrannosaurus Rex and possible other theropod dinosaurs with similar skull anatomy of the upper and lower mandibles more than likely had thickened yet sensitive skin with a lip like structure similar to that of waterfowl and not a scaled skin.

Additional research papers on duck bill anatomy/mechanreceptors

Histomorphogenesis of Upper Beak in Muscovy Ducks (Cairina moschata)

3D architecture and a bicellular mechanism of touch detection in mechanosensory corpuscle

Molecular basis of tactile specialization in the duck bill

Personal Notes on research

[knarme-art]

Ceratosaurus and allosaurus heads, as a little experiment... Sizes aren't up to scale, just wanted to color and edit a sketch of mine digitally.

[joitiks]

cryolophosaurus ellioti, a large theropod from early jurassic antarctica

commission info

[palaeosinensis]

Alright science art and paleo art folks go gentle on me. If I was to do these for a gallery showing I think I'd need at least a couple of weeks for research and notes alone. More if I reached out to researchers for paper access and feedback. Speculative armored invertebrates, Dickinsonia, speculative medusa, Charnia, Spriggina, Kimberella, Arkarua, & their trace fossils.

[troodontid]

protosuchus sniff you now

[raptorbricksart]

Deep in the ancient oceans, lurks the mighty Dunkleosteus. A bit of Blockbench paleo art from a little while back i never posted.

Based on the recent, more rotund, reconstruction of D. terrelli, still quite the fearsome beast!

Been some time since i did any paleoart so it was great to finally get back to it again!

Let me know what you think!

[fossilprep]

Yesterday our paleo crew got together to get some of our best specimens CT scanned at CHI St. Alexius Hospital in Dickinson. The scans are already revealing things about the internal processes of dinosaur skulls that wouldn't normally be visible. Much more will be elucidated upon further study.

We aim to reconstruct our Lambeosaurus' resonating chamber to hear its honk, show off the D. wilsoni holotype's replacement teeth and abscess, and see just how small ceratopsians' brains really were.

[mcromwell]

*presses my face against the askbox*

You reblogged dinosaur post. Is this ... perchance foreshadowing of dinosaur drawing????????????????????????????????????????????

No pressure if no but I now cant stop thinking of dinosaurs in the way you might potentially draw them

💕💕💕💕💕💕

I do enjoy me a dinosaur!! I reblogged that because my friend Hazard made it and I was the one who supplied the duck specimens for it, and it's super interesting and I think paleo art and reconstructions are sick! I have thought of doing dinosaurs before, though, so all we're waiting for is the mood to strike. Hee hee. Spoilers: my favorite dino is parasaurolophus.

Here's a piece I did in 2020 of a dilophosaurus for my friend's tattoo shop, Jurassic Ink in Federal Way, WA.

(As you can see it's not terribly scientific, har har. The hardcore scientific illustration/paleoart community doesn't seem like my jam. Respect to them, just not for me.)

[barghest-land]

Hello! I have an advice question if you have the time and inclination. I would like to draw better extinct animals and I am wondering if you have any advice for putting meat on old bones. I know I need to do anatomical studies, and I'm familiar with all yesterdays/not shrinkwrapping. However, when faced with a fossil, I don't know where to start. I've tried looking up papers where they model the muscles, but those are usually 1 leg, or a jaw, so not particularly helpful for illustration. What's your thought process? Your illustrations look so real. I know part of that is your lovely handling of light and shadow, but the animals have real heft to them.

hiii!! ahh i'm probably not the best person to ask tbh, sorry. but i'll try to help as much as i can and explain how i do things:

i still don't feel confident enough in my paleoart. i came to paleoart from "art" part, not from "paleo", so if we talk about science, i know very little. i'm still trying to learn myself and do studies whenever i can, so i can't really explain things in a scientific way. however, there are some things that are helping me to learn: i have a good knowledge of anatomy in general, so if you study extant animals and how their anatomy and muscles work, it helps to draw those who are extinct. it's a really good base, and a lot of references you can work on! and while you're working on those, you can also study light and shadow, that helps to understand the shapes as well. if you want to be more confident in paleo, i think it's easier to start with an extinct animal that is well known, has muscle 3D models, good skeletal drawings, etc. it will help you more than looking on a jaw fragment and not knowing what to do with it (trust me i've been there). also, when it comes to paleo, and especially soft tissue, a lot of it is speculation. for most of the species info about it isn't known at all, so you can do something fun with it! having fun with speculation might be scary (i know it well i'm still scared lol), because you don't know what you can draw, will it be wrong or not, but the answer is - we don't know how most animals looked like, so the fear of making a mistake goes away with practicing and allowing yourself to speculate here and there. for example: if you know how to draw a well studied pterosaur, and later want to draw their relative that is known by only the fragment, you'll be more confident to do so, because you'll know their base features already. so when there's some animal known from a tiny piece of a bone and not much is known, i think the safest way is to look at their closest relatives that are more studied. that definitely doesn't hurt, especially with new described species that don't even have any reconstructions yet. long story short (from the artistic point of view since i don't have another): study living animals, gain confidence drawing well studied extinct ones (you'll have more references there and it's less confusing for a start!), and most importantly have fun! <3 ah and also, there are places where you can get a feedback on your drawings from paleo people. i ask for it often, especially when i'm drawing something far from my comfort zone. i'm learning a lot from my mistakes and it feels good tbh:)

[mineralsrocksandfossiltalks]

Science Saturday: Paleosols

Paleosol literally means "ancient soil." In geology and paleontology, a paleosol is a former soil preserved by burial under alluvium, loess or volcanic deposits.

Paleosols are frequently used to help determine the climate when they were deposited.

Figure 4. Photos illustrating paleo-Vertisol features in the Yellow Cat Member at Poison Strip, Utah (Figure 1; PS), where local conditions have maintained exceptional paleosol exposures of far greater quality than those at Utahraptor Ridge (Figure 3). (a) Two stacked paleosols (ps1, ps2); ps1 contains several carbonate-filled cracks (horizontal white arrows), and ps2 exhibits a zone of prominent, filled soil cracks (sc). Pathways of the downward translocation of sandier soil material from above into clayey soil material below are shown for selected cracks as yellow arrows at the left. (b) Closeup of soil cracks (sc) in ps2. (c) Another paleosol (ps) with prominent slickensides, identified by diagonal white arrows; general sense of shear along slickensides is shown by yellow arrows. Shear within this Early Cretaceous soil profile moved materials obliquely up and down. Features shown in these photographs suggest that perfect stratigraphic superposition (e.g., of paleosol organic matter and volcanogenic zircons) is very unlikely to exist within these paleosol profiles due to ancient pedoturbation. We propose that conditions were similar at Utahraptor Ridge during the Early Cretaceous (see text for further discussion).

(Joeckel et al, 2023)

A vertisol is a swelling clay soil. Swelling clays have a significant amount of ash in them which causes them to expand when wet. These clays tend to be incredibly sticky, adding 10 pounds to your feet in minutes. This indicates that there was likely some active volcanism during the early Cretaceous.

Paleosols can also be used to reconstruct paleo atmospheres. Oxidized paleosols like the red clay in the photograph above could indicate a rise in atmospheric oxygen.

Paleosols often contain fossilized pollen which tells a lot about ancient ecosystems.

Who knew old dirt could be so informative!

[prettycreepyprettycrawly]

I made a small attempt at some paleo-reconstruction! Here we have a couple creatures from the White Sea assemblage--Kimberella and Charnia. I choose to believe the Ediacaran period was soft and pastel colored

[datgreenmonstah]

“Entelodont Daedon”

Updated my rough sketch on this guy and worked on the body and feet more, I feel satisfied with how they look now, gonna keep the red cause it’s a color and markings that have grown on me since working on reconstructing this weirdo.

I hope you enjoy their new slippers, looking at ungulate foot bones to compare anatomy and concluded they resemble closer to a camelid/pygmy hippo than to a bovid or other hooded ungulates.

Still working on the nose, but I think I might have it down finally. Been comparing a lot of nasal bones and their structures to get a better build on this guy.

[knarme-art]

If everyone in the internet was an allosaurus, he'd get told to "cover it up!!" for posting a selfie like this. u_u

[synapsid-taxonomy]

Hello fellow synapsid! φ(゜▽゜*)♪

For an Easter joke, I was going to do a cartoon-esque illustration of Kollikodon. It's a Cenomanian (~99-96 MYA) monotreme with "bun like molars". There isn't much material, so I was going to go with a "well, if NO ONE ELSE was going to suggest this common ecological and phylogenetic attributes" approach.

Thing is, I haven't done an independent paleo reconstruction before, and all the material that's known is the right maxillary. Also, as committed to the joke as I am at this point, mammals aren't really my strongest of interest.

I'm worried that, since it's an obscure genus with few illustrations, my depiction might give people the wrong impression of what the animal was like... But I don't like being TOO conservative, especially when a gut feeling is telling me that certain approaches in speculation are viable, but unexplored.

Do you have any advice? Common mistakes, pitfalls I should avoid, how many pages a day should I speed read Witton's paleoartist's handbook, other folks to asks for advice? Things that'll help me be a better paleoartist.

I also know you don't specialise in paleoart, but since this is a case for a synapsid, you were the first person I thought of to ask for advice.

First step is starting with what we know. Thing with Kollikodon is that all we have is this:

It seems to be a stem-monotreme, decently close to the monotreme crown. Based on all other monotremes (including the extinct Kryoryctes and Steropodon), we can guess that its body was relatively stocky and short-limbed. It's outside the clade that we know had the beaks present in platypi and echidna, though we don't have enough to say for certain that it didn't have one. Should also be noted, though, that its teeth imply a different ecology from either of them. Its molars are bunodont (flat, quadrangular, multicusped), and bunodont molars are common in generalist omnivores (humans have somewhat bunodont molars), but the unusual morphology of Kollikodon's molars implies that it might have been doing more crushing than the average generalist.

The thing about something as fragmentary and enigmatic as this is that lots of speculation is necessary to portray it at all. But the flipside is, there are many ways to do it that aren't wrong. So a lot of it's up to you. If you want to avoid giving people the wrong impression of what it's like, then try to avoid features that are "out of left field" so to speak. Things that we don't see in monotremes or that we wouldn't expect in a generalist omnivore are less likely to be present in Kollikodon based on the data we have. For example, all known monotremes have relatively short limbs, and you don't necessarily need particularly long legs if you're a generalist, so it's safest to give it relatively short limbs. So keep in mind what it's related to and what life it was probably living, and have fun with it from there, is what I'd say.

And if you want some more paleoart-focused advice, there are a whole bunch of paleoartists on Tumblr! @i-draws-dinosaurs, @knuppitalism-with-ue, @aberrantologist, @ppaleoartistgallery, @alphynix, @dinodanicus, and @usik-paleo-illust are just a few, and you can find many more are in the #paleoart tag. I'm not an artist, so I recommend reaching out to some of them if you want some more experienced tips!

[greenfrog04]

A new pterosaur specimen from the Lower Cretaceous Yixian Formation of Liaoning Province, China: The oldest fossil record of Nurhachius

Published 28th June 2023

A new fossil specimen of the Istiodactylidae Nurhachius from the Liaoning Province.

Image of the Liaoning Province, from Wikitravel.

Nurhachius ignaciobritoi described 6th October 2005.

Nurhachius luei holotype (BPMC-0204), described 19th September 2019.

Nurhachius is an almost mature pterosaur with an estimated wingspan of 1.6 m and is geologically the oldest known occurrence of Nurhachius. The istiodactylidae is a new component of the pterosaur assemblage of the Jingangshan Member, and provides new information on the pelvis and hindlimb of istiodactylids and the palaeobiology of this clade. A great discovery that provides more information for the pterosaurs in China.

Skeletal reconstruction of Nurhachius, from:

note that this reconstruction may not be reliable or accurate and may be a speculative/innovative creative vision of Nurhachius' appearance (note added in response to feedback, thank you! I'll make sure to include disclaimers/warnings in the future for less trustworthy sources)

Paleo art of Nurhachius, on Wikipedia.

Source:

read the paper for more information.

[a-dinosaur-a-day]

hi, I'm a student looking to maybe go into paleontology! I love your blog, and I've just got a few questions if that's alright!

How did you get into paleontology?

How did you end up becoming a paleontologist (as in, what subjects and such helped)

and what do you do on the job?

Sorry for all the questions, I'd just like to know more about being a paleontologist!

Hi! So

There are a LOT of ways to get into paleontology

The field has multiple parts:

Geologists who focus on the rock content and depositional environment and the context each fossil is found in

Biologists who focus on what the fossils were like when they were alive

Artists who do their best damn job to take all of the evidence and reconstruct the organisms as they were in life

Paleoartists are just as much part of paleontology as the rest of us! In fact, paleoart is an important part of the science.

I personally got into paleontology via option B, Biology. I majored in biology in college and then got a master's degree in evolutionary biology. I also kept up with paleontological papers, read a lot, and constantly challenged my own assumptions.

In undergrad, I did research on paleo, too - that's a big help. I got to organize a Burgess Shale collection and identify all the organisms. Getting a research position in undergrad is a major help to getting your foot in the door.

The way I got into my paleontology PhD program was via networking, unfortunately. There are a lot of conferences year round about paleontology, and lots of people - enthusiasts, wanna be scientists, but also fully fledged scientists and researchers - attend them. I met my advisor, Dr. Peter Houde, at one such conference (Society of Vertebrate Paleontology Annual Meeting). We chatted, he realized I had a lot of research interests in common with him, and I applied to work with him.

Evolutionary Biology, Anatomy, Physiology, and Ecology are the big biology subjects that every paleontologist needs to know. We need to know how things evolve, how their bodies work, and how they interacted with each other and their abiotic environment.

In terms of geology, the big things there would be Sedimentology, Stratigraphy, Geochronology, and Geochemistry. Understanding how sedimentary rocks form, how things fossilize within them, how we measure deep time, and what the different chemicals in fossils and rocks mean for that organism's history are all necessary components.

I would also take drawing classes, specifically so you can draw what you observe in the field. I never did and I regret it.

In terms of how I fell in love with paleo originally, well, my parents showed me Land Before Time when I was like, one, and I fell in love instantaneously. I spent most of my childhood reading dinosaur books, through high school. I just kind of never stopped being obsessed.

On the job, I mostly look at fossils at a lab bench, prep them with very basic chemicals (so nothing too dangerous most of the time), and look at their traits. I also scour databases and gather lots of information about what I need to know. There's some programming, some excel work, graphing, lots of basic stuff. I also have to write a loooot. I don't do fieldwork, because I'm disabled and fieldwork is hella unaccessable, but there's lots for me to do at the bench!

I can go into it more, but I think that's a good start.