Hayley Orlowski

You can't watch Jennifer's Body as a biologist, because you'll spend too much time wondering why there's a musk deer in the temperate rainforests of northern Minnesota.

Tying the knot between morphology and development: using the patterning cascade model between cheek teeth to study the evolution of molarization in hoofed mammals - Journal of Mammalian Evolution Hoofed mammal premolars show a range of occlusal crown morphology from molariform to caniniform, and the position of taxa on this spectrum can be described as the relative molarization of the premolars. Molarized premolars function together with the molars in grinding mastication in which these unique premolars appear. The degree of molarization varies across dietary ecologies, which has led to cheek tooth morphology being designated as an important contributor to dietary predictions in extant and extinct taxa. Recent research into mammalian occlusal cheek tooth patterning have found independent patterning mechanisms of the premolars and molars. A research gap exists in understand how molarization of the premolars has occurred so frequently in hoofed mammals if these dental regions are independent in their patterning. In this study, we tested the application of the patterning cascade model to the lower premolar-molar boundary in hoofed mammals using a geometric morphometrics framework. We used 2D geometric morphometrics to study occlusal cuspid covariation at the lower p4-m1 boundaries of 16 artiodactyl and 18 perissodactyl species. Phylogenetically informed modularity analyses were used to test alternate a priori hypotheses originating from evolutionary, developmental, and functional considerations of cheek tooth morphogenesis. Our results showed artiodactyls and perissodactyls differ significantly in their p4-m1 boundary covariation patterns, which we hypothesize could be caused by heterochronic shifts between premolar and molar development. To our knowledge, our study is the first to contribute a comprehensive yet accessible 2D geometric morphometric method to further investigate the evolution of molarized premolars.

Ashbaugh, A.J., Jamniczky, H.A. & Theodor, J.M. Tying the knot between morphology and development: using the patterning cascade model between cheek teeth to study the evolution of molarization in hoofed mammals. J Mammal Evol 32, 23 (2025). doi.org/10.1007/s109...

Mitochondrial genomes of Middle Pleistocene horses from the open-air site complex of Schöningen - Nature Ecology & Evolution Mitochondrial DNA from horses at the Middle Pleistocene archaeological site of Schöningen reveals insight into the evolutionary history of horses and advances techniques for the analysis of ancient DNA retrieved from highly degraded samples.

www.nature.com/articles/s41...

Always "funny" to find plagiarism in scientific papers, especially ones from the last five years...

More of this on museum signage, please

this feels like an incredible new urban legend taking shape on reddit otoh I've lowkey seen this happen. like jerusalem syndrome but for talking to the computer

Whenever some new dinosaur drama drops I love imagining what it would be like if we acted the same way whenever a new Miocene horse paper comes out.

New publication! My first dissertation chapter is now published in @plosone.org with @paleobadger.bsky.social, @calamanderso.bsky.social, Hannah Miller, Max Deckman, and Brandon Price. Any images not credited below are from this paper.

doi.org/10.1371/jour...

@uwmadscience.bsky.social

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Results from the #paleostream!
Ojoceratops, Leidyosuchus, Hemiauchenia and Bienotheroides.

🤦‍♀️

oof 😣 It's crazy how central this stuff is to biology and how obscure it is to the general public!

Honestly the best part about getting into the latter part of a graduate degree is not having to sit though that anymore

happy "explain phylogenetics" week to every biology instructor on earth

same methods, different era

about to get my h-index up

"Lord of Plains" - faux woodblock/linocut style art of a heavily stylized Przewalski's horse. Intended as part of a series with the Lord of Meadows piece. #art #horse #wildhorse #fauxlinocut #linocut #illustration #printmaking

Don't do this.

on the phone with my lawyer this very moment

UH OH

only dinosaur fossils though because i think their small sample sizes are funny and want them to be even smaller

my "i eat fossils when no one else is looking" shirt at the natural history museum is raising a lot of questions already answered by the shirt

It's hard. As someone who's in a very early career stage it definitely feel like there's a push to go for the broad-scale, big-picture thing that's more likely to get recognition and citations to help build a career. And that stuff's important...but it's all built on the "grunt work".

"I maintain strongly that every young paleontologist should have fundamental training in the careful examination and description of fossils. This is essential not only for altruistically taking one’s share of the vast task still before us but also because there is no other way of getting to know fossils properly. By all means let the Ph.D. candidate combine a paleoecological study with a revision of the fauna or flora concerned, but he should not think that he can just sample the cream and leave the very nourishing milk to someone else."

I think of this quote from Derek Ager (1963):

Screenshot of the wikipedia page for Merychippus, a proto-horse that lived in North America 15.97-5.33 million years ago. It had three toes on each foot.

Merychippus everyone 🎄🐎

I don't know, but late-19th-century horse papers go about the same for me.

Can you tell why one of these is referred to as a "stilt-legged horse"? The taxonomy of these guys is contentious, and it's not helped by the fact that it can be hard to tell them apart from more standard-shaped horses... #FossilFriday

So why am i driving this one in this weather??

Plus horse taxonomy is dominated by invalid taxa - about 900 have been named of which ~300 are valid.

Interesting. Very different curve from fossil horses.

Close up detail of the background of a piece I am currently working on showing three Pleistocene horses

Commission WIP. Close up of detail in the background

#paleoart #sciart #pleistocene