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Armin Reindl @arminreindl.bsky.social · 17h

Both relevant papers:
doi.org/10.1643/0045...
doi.org/10.1098/rsos...

A New Miniature Horned Crocodile from the Quaternary of Aldabra Atoll, Western Indian Ocean

A new crocodylid is described on the basis of fragmentary, but diagnostic, material from the Quaternary of Aldabra Atoll. It differs from all other known crocodylians, living or extinct, in having a p...

https://doi.org/10.1643/0045-8511(2006)6[149:ANMHCF]2.0.CO;2

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Armin Reindl @arminreindl.bsky.social · 17h

Artwork above by Manusuchus
Late Pleistocene fossils of giant tortoises from the Seychelles also bear the bite marks of crocodilians, suggesting that Aldabrachampsus, or another crocodilian, either killed or scavenged them, giving us this brilliant figure from Scheyer et al 2018

An illustration from Scheyer et al 2018 showing two scenarios on how crocodilian bite marks may have ended up on the shells of a giant tortoise. The top illustration shows the animal submerged underwater, slowly approaching a drinking tortoise. The illustration below shows the crocodilian coming out of the water to feed on the corpse of an already dead tortoise, surrounded by flies and a coconut crab.

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Armin Reindl @arminreindl.bsky.social · 17h

#Croctober Day 12
Probably among the most obscure recently extinct crocodilians is Aldabrachampsus, a small (up to 2.5 meter) long animal of uncertain placement with a pair of rounded squamosal horns that lived on the Seychelles around 100.000 years ago

An illustratoin of Aldabrachampsus by paleoartist Manusuchus. The illustration shows the animal as similar to modern dwarf crocodiles with a short, blunt snout, interlocking teeth, large bulging eyes but different in having large, rounded horns above the ears.

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Armin Reindl @arminreindl.bsky.social · 1d

And the paper doi.org/10.1016/j.gr...

Redirecting

doi.org

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Armin Reindl @arminreindl.bsky.social · 1d

For #Croctober Day 11 we got Confractosuchus (art by Julius Csotonyi)
Confracto once inhabited the Winton Formation of Australia, but unlike the tiny Isisfordia was sizable enough to even feed on dinosaurs. Which we know because we found the bones of an elasmarian in its stomach

$Paleoart and a 3D scan of Confractosuchus. On top the animal (drawn by Julius Csotonyi) is shown lunging out of the water in a wooded region, a small elasmarian ornithopod in the process of being swallowed. The graphic below it shows a 3D scan of the fossil material, the skull largely resembles modern crocodiles.$

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Armin Reindl @arminreindl.bsky.social · 2d

Our fun fact for #Croctober day 10
Crocs even developed beaks at some point. Macelognathus (art by Scott Reid) is an early crocodylomorph from the Morrison Formation who's lower jaw tip was flattened and beak like with teeth further back in the jaw.

An illustration of the lower jaw of Macelognathus. The tip of the snout is expanded and flattened, somewhat resembling a wider duck bill. Behind the beak section multipole toothsockets are visible.

Paleoart of Macelognathus by Scott Reid. The animal has a long tail and incredibly lanky legs, almost resembling a windhound more than a crocodile. The skull is narrow and triangular with rows of teeth and a beaked tip.

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Armin Reindl @arminreindl.bsky.social · 3d

Aetosaurs are an interesting group that I want to dig deeper into at some point (if I find the time), but rest assured the osteoderms are incredibly distinct in these guys
This does mean that frustratingly theres a bunch of species just named from a handful of armor plates tho

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Armin Reindl @arminreindl.bsky.social · 3d

It's shown quite nicely in this illustration of Gorgetosuchus by Matt Celeskey

An illustration of Gorgetosuchus by Matt Celeskey. The animal is shown in 3/4 view from behind. It is heavily armored with a triangular snout and a broadened nose tip. A close up shows the overall appearance of a ring of osteoderms, with notes describing its anatomical details.

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Armin Reindl @arminreindl.bsky.social · 3d

While the osteoderms are isolated, we can see the anterior bar in the bones of Rioarribasuchus, therefore we can tell whats the front and whats the back of each osteoderm and therefore see that the spikes curve forward

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Armin Reindl @arminreindl.bsky.social · 3d

Great question, the reason we know is due to how the armor of aetosaurs interlocks. Generally speaking, aetosaur osteoderms overlap the ones behind them, and the region that is overlapped is known as the anterior bar (its really obvious in some species).

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Armin Reindl @arminreindl.bsky.social · 3d

Really its an entire saga I do recommend reading up on, thankfully a lot of the procedure has been thoroughly documented by Mike Taylor and Darren Naish around the time of the events in 2007/2008

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Armin Reindl @arminreindl.bsky.social · 3d

Of course the case of Rioarribasuchus/Heliocanthus was not the only thing to cause Aetogate, another notable case is what was the New Mexico team seemingly plagiarizing or at least taking credit for the findings of Jeff Martz (illustrator of the first image) and other such cases

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Armin Reindl @arminreindl.bsky.social · 3d

changing their mind, publishing an incredibly brief (not even 2 full pages) report coining the name Rioarribasuchus before Parker was able to publish his own study, which would have named the animal Heliocanthus

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Armin Reindl @arminreindl.bsky.social · 3d

a sentiment that William G. Parker did not share, instead suggesting that the animal was its own distinct taxon that was yet to be given a name (something Parker was working on).
The New Mexico team continued to refer it to Desmatosuchus, that is until suddenly...

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Armin Reindl @arminreindl.bsky.social · 3d

So Aetogate is a controversy that took place in the late 2000s when several researchers of the New Mexico Museum of Natural History were accused of plagiarism. In the case of Rioarribasuchus for instance the animal was long considered a species of Desmatosuchus...

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Armin Reindl @arminreindl.bsky.social · 3d

Day 9 of #Croctober, featuring Rioarribasuchus
Outwardly a fascinating and imo quite underappreciated animal given the strange, forward-pointing spines on the tail scutes
But while it looks unique, Rioarribasuchus is better known for being central to the Aetogate controversy

An illustration of "Rioarribasuchus" by Jeff Martz. It is shown as a robust animal with extensive armor plating and a small triangular head. The front limbs are shorter than the hindlimbs and the tail features a ridge of forward pointing spines throughout most of of its length.

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Armin Reindl @arminreindl.bsky.social · 4d

But for a more thorough description go see doi.org/10.1080/0272...

Articulated skeletons of the aetosaur Typothorax coccinarum Cope (Archosauria: Stagonolepididae) from the Upper Triassic Bull Canyon Formation (Revueltian: early-mid Norian), eastern New Mexico, USA

We report two nearly complete, articulated skeletons of the crurotarsan archosaur Typothorax coccinarum from the Upper Triassic Bull Canyon Formation of east-central New Mexico. These are the mos...

doi.org

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Armin Reindl @arminreindl.bsky.social · 4d

Part of me thinks this might be the most well known thing I've covered so far, but at the same time I hardly know what people are actually aware of and how much is just nische knowledge
anyways the figure is from Lucas and Heckert 2011

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Armin Reindl @arminreindl.bsky.social · 4d

For day 8 of #Croctober I'm going way back.
This is Typothorax, an aetosaur from the Triassic of New Mexico best known for how well armored it was.
In fact it was so well armored even the cloaca is surrounded by an arrey of osteoderms

The skeleton of Typothorax in multiple views. The very top shows a fossil, flipped on its back and missing the head but nicely showing the osteoderms. Below that a lateral view of the skeletal reconstruction shows the animal had short frontlimbs and longer legs, a tiny head and a plump body covered in armor. The ventral view shows how even the cloaca was surrounded in bony scutes and a front view highlights not just how tiny the head is but also how square the body is proportioned.

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Armin Reindl @arminreindl.bsky.social · 5d

Boverisuchus meanwhile is a planocraniid, a family of Eusuchia (or maybe even Crocodilia) that ranged across essentially all of former Laurasia, with members having been found in the USA, Europe and China.
If you're unfamiliar with the name, its basically Pristichampsus

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Armin Reindl @arminreindl.bsky.social · 5d

Artwork by Scott Reid and Corbin Rainbolt
Despite shared terrestrial habits, the two are not related, with Bergisuchus being a member of the clade Notosuchia that managed to persist into the Cenozoic, tho the origins of European members remains somewhat nebulous

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Armin Reindl @arminreindl.bsky.social · 5d

Day 7 of #Croctober
The Messel Pit in Germany is well known for its fossil crocs, which includes not one but two distinct lineages of terrestrial forms.
On the one hand the sebecoid Bergisuchus dietrichbergi, on the other the eusuchian Boverisuchus magnifrons

A digitall painting of Boverisuchus by Corbin Rainbolt. The animal is shown barreling through the underbrush of an ancient rainforest, chasing down a tiny early horse. Compared to Bergisuchus the head is a lot more similar to modern crocs, although boxier and not as flattened.

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Armin Reindl @arminreindl.bsky.social · 5d

Thank you so much. I just enjoy sharing my passion in crocs where possible

Armin Reindl @arminreindl.bsky.social · 5d

I hate to say it but the pun did cross my mind at one point lmao

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Armin Reindl @arminreindl.bsky.social · 6d

Also big shout out to Adam Yates not just for his tireless croc research but also for thinking my recons were good enough to be included in that graphical explanation you see in the first post

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