Z. Jack Tseng
@tsengzj.bsky.social
Paleontologist at the University of California, Berkeley. Interested in Functional Anatomy and Vertebrate Evolution. Self-proclaimed paleomammalogist.
New pre-print testing if bats, carnivorans, & primates occupying equivalent dietary niches evolved convergent mandible shapes & shared adaptive zones! Short answer: no. With @mberthaume.bsky.social, @savannahecobb.bsky.social, & @sesantana.bsky.social www.researchsquare.com/article/rs-1...
New paper out on dietary signals in tooth topography vs morphometrics, first-authored by the impressive Melvin Vankelst in the @val-fisch.bsky.social lab! FAVE Lab had the pleasure of hosting Melvin for this and other research activities during a semester-long visit earlier in the year.
Prof. Valentin Fischer@val-fisch.bsky.social · 3d agoNew paper by Ph.D. student Melvin Vankelst in Proc B. We modified our semi-automated high density 3D geometric morphometrics protocol to fit carnivoran molars, and test the shape-diet links of these teeth. Check it out! @universitedeliege.bsky.social royalsocietypublishing.org/rspb/article...
Second paper out today on fossil carnivorans, this time in Biology Letters @royalsocietypublishing.org. We looked at the evolution of the body mass of carnivorous mammals throughout the Paleogene, comparing the patterns in Europe vs USA 1/3
New paper by Ph.D. student Melvin Vankelst in Proc B. We modified our semi-automated high density 3D geometric morphometrics protocol to fit carnivoran molars, and test the shape-diet links of these teeth. Check it out! @universitedeliege.bsky.social royalsocietypublishing.org/rspb/article...
Decoupling geometry and topography reveals contrasting ecomorphological signals in carnivoran carnassial teeth
Abstract. The lower carnassial tooth (m1) is a key innovation underlying the ecological diversification of Carnivora. However, their exceptionally diverse
royalsocietypublishing.org
African wild dog (Lycaon pictus) paper now in @anatrecord.bsky.social's Feeding Biomechanics Special Issue! Using dissection & diceCT, we show powerful bites aren't just about bigger muscles—muscle architecture, skull mechanics & fascia may be key🐺 anatomypubs.onlinelibrary.wiley.com/doi/10.1002/...
#FossilFriday flashback: My lab published two major papers this month on 1) dental functional morphology and 2) vertebrate paleontology & paleobiogeography. It made me so proud of the research teams I've been a part of over the past decade, but it also prompted reflection on my academic path (🧵1/5)
An informative and interesting thread on the tectonic perspective to the question of isthmus formation tempo and mode:
Brandon Bishop@brandontbishop.bsky.social · last wk.This is a good thread on a good paper, but I want to point out that pretty much *all* studies of the Panama-South America suture require it to have been in place by ~12-13 million years ago, and most would have that bit of the isthmus as above water then, too.
An analysis of fossil mammals in Science suggests that Mexico served as a long-term evolutionary “holding pen” where North American species adapted and diversified for millions of years before sweeping into South America 2.8 million years ago. https://scim.ag/4fu2QKL
Here is @ucberkeleyofficial.bsky.social Bob Sanders' write-up of our Great American Biotic Interchange work: news.berkeley.edu/2026/07/30/n...
North and South America weren’t always connected, but their mammals still found a way to intermingle - Berkeley News
Before the Panamanian land bridge formed about 3 million years ago, mammals on the two continents were isolated — or so biologists thought. New fossils show that they found ways to mix long before tha...
news.berkeley.edu
Exhilarated to share a 2nd @science.org cover article this month from our lab @ucberkeleyofficial.bsky.social! A collaboration with US & Mexico colleagues on the role of a Mexican biogeographic holding pen in shaping the Great American Biotic Interchange (GABI)(1/11) www.science.org/doi/10.1126/...
ABSTRACT SUBMISSION DEADLINE for #AGU2026 COMING SOON (🗓️August 5 🗓️)! 🚨Don't forget to submit your abstract for our paleo session 🦖 The Future of the Fossil Record: Developments, Trends and Innovative Approaches in Paleontology 🔗 tinyurl.com/mtkyptc7 See y'all in San Francisco 🌉
New fossil fish dropped! Meet Jianghanichthys huachongensis sp. nov. Despite fragile, swampy origins, exceptional preservation of its head sensory canals is shedding new light on Cypriniformes evolution! cdnsciencepub.com/doi/full/10.... #Paleontology #Ichthyology #Fossil #NewSpecies #Evolution
#FossilFriday explainer thread for our latest study on the canalized evolution of the tribosphenic carnassial tooth (with ancestrally 3-cusped talonid and trigonid regions) in carnivorous mammals. An example of how a prior evolutionary innovation can narrow the potential for subsequent change.
Narimane Chatar@narimanechatar.bsky.social · 3w agoExcited to share our latest study highlighted on the cover of @science.org 🥳Combining a 3D dataset representing 250 taxa spanning the whole Cenozoic, 3D modelling & printing and material testing; we deciphered the form-function relationship in the lower 🦷 of mammals www.science.org/doi/10.1126/...
Finally, when looking at the trade off between the two function something became quickly evident: it is quite rare to find a tooth very efficient at both functions. Fewer than 1% our dataset sat on the Pareto font of optimality
This was further supported by phylogenetic comparative methods: phylogenetic signal is consistently stronger in slicing metrics. In short, all efficient slicers look the same and are closely related
Our analyses show that each of the two recurring morphotype previously highlighted appear specialized for one function (slicing or crushing) but also that efficient slicing seem to be more morphologically constrained to a narrow set of phenotypes
We used a stack of medical gelatin to simulate the penetration of a multi-layer system (e.g. skin, muscle, fat) and a bone modelling filament to simulate the crushing of hard tissues
Then, we had to find a way to quantify the functional aspect. To do so we developed a protocol to quantify to very antagonistic functions: slicing and crushing
Our GMM analyses reveal two recurring shape in the lower carnassial on carnivorans and ‘creodonts’
We gathered scans of 250 species spanning the whole Cenozoic, isolated their lower carnassial and quantified the shape using a semi automated high density landmarking protocol
The carnassial is a very interesting topic: it appeared multiple times in mammals but the only extant placentals bearing those specialized pair of teeth are the carnivorans. Therefore, the lower carnassial of carnivorans and “creodonts” was chosen as a study system
Carnivorans represent an amazing study system: with lower molars showing high disparity, some species retain lower carnassial resembling the tribosphenic molar, some generalists and some specialists
One of the dental breakthroughs in mammals is the tribosphenic molar: a tooth allowing crushing and slicing in a single stroke with its 2 distinct regions. However, the evolutionary implications & consequences of potential trade-offs between those two functions are unclear
Excited to share our latest study highlighted on the cover of @science.org 🥳Combining a 3D dataset representing 250 taxa spanning the whole Cenozoic, 3D modelling & printing and material testing; we deciphered the form-function relationship in the lower 🦷 of mammals www.science.org/doi/10.1126/...
🎉Another UCMP paper in Science, this time on the cover! 🎉
Z. Jack Tseng@tsengzj.bsky.social · 3w agoOur newest paper on mammalian dental evolution, out today as the cover article in @science.org, lead by @narimanechatar.bsky.social with a team of fantastic early career scientists!!! 🎉🥳 “Performance trade-offs define a fundamental dental dichotomy in mammals” www.science.org/doi/10.1126/...
Our newest paper on mammalian dental evolution, out today as the cover article in @science.org, lead by @narimanechatar.bsky.social with a team of fantastic early career scientists!!! 🎉🥳 “Performance trade-offs define a fundamental dental dichotomy in mammals” www.science.org/doi/10.1126/...
Excited for a major paper drop tomorrow with @narimanechatar.bsky.social! Watch this space if you like mammals and teeth!
I'd like to ask you to consider helping our people during this unprecedented catastrophe, either now or in the future as the media attention fades. This curated directory has an excellent list of opportunities to help through reputable organizations: donarseguro.com/en. I can't thank you enough! 2/2
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donarseguro.com
A week ago, two massive #earthquakes hit my beloved birth country, #Venezuela. Despite heroic efforts by civilians and international rescue teams, the dead toll is rising, >40,000 people are still missing, and thousands were injured and/or lost their homes. 1/2> youtu.be/3LhZ6Xf10CI?...
Drone video shows collapsed buildings in Venezuela after earthquakes
YouTube video by Associated Press
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