Top right: Photograph of two jaw bones with a one cent Euro coin for scale. The bones are a fragment of a mandible of Galanthis baskini from Las Casiones (small, darker specimen, above) and a complete mandible of the extant species Mustela nivalis (lesser weasel; lighter coloured specimen below). Image: Alberto Valenciano. Top left: blue rectangle is a cover image from the journal Palaeontology. Bottom: Illustration of body mass along the branches of the tip-dated Bayesian MCC tree, showing the ancestral body mass for each clade; illustrated specimens (not to scale): Lutra lutra, MNCN-3666; Vormela peregusna, IVPP-OV519; Zdanskyictis minimus, PMU-21788; Mustela putorius, MNCN-3846; Mustela nivalis, MNCN-14416; Mustela erminea, MNCN-14372; Neogale vison, MNCN-14417; Galanthis baskini, KS-9a; Martes americana, FMNH-51372.

Oldest evidence of a weasel reveals a Miocene origin of the Mustelinae (Mammalia, Carnivora) onlinelibrary.wiley.com/doi/10.1111/... @morphobank.bsky.social

The discovery of G. baskini supports current hypotheses that expansion of open habitats & rodent diversification during the mid- to late-Miocene spurred the evolution of body plans that were small & flexible to chase rodent prey in crevices & underground. 🧵 3/3

www.washington.edu/news/2026/04...

Comparison between a jaw fragment from Galanthis baskini (top) to a complete mandible of the least weasel (bottom). A European cent is shown for scale. Photo: Alberto Valenciano

G. baskini was also the size of the least weasel, suggesting that small body size was present from the very beginning of their evolution! 🧵 2/3

Oldest evidence of a weasel reveals a Miocene origin of the Mustelinae (Mammalia, Carnivora) Weasels are among the most widespread small carnivores, playing a key role in extant Holarctic ecosystems by preying on other small vertebrates. Despite their substantial diversification during the P...

Introducing the world's oldest weasel, Galanthis baskini! Led by Alberto Valenciano, we found that this weasel dates back to at least the Late Miocene (6.56–6.26 Ma) and pushes the origin of weasels by ~3 million years! 🧵 1/3

onlinelibrary.wiley.com/doi/10.1111/...

Hi all. I am very excited that after 6 years I finally got my phylogenetic comparative methods book and online exercises online. Feel free to use and share. The book is here: nhcooper123.github.io/pcm-primer/. Note that it is not finished, we had to abandon it before the sunk costs fallacy broke us

Killer tortoises! I showed this in my island biology lecture yesterday and it shocked the students 😱 Here's the paper describing the behaviour: www.cell.com/current-biol... 🧪🌏

Fun to share a bit about the last 4 years of undergrad led research at the #SSB2026 meeting! @systbiol.bsky.social

Summer fish class at Friday Harbor Labs 🐟
5 weeks, field + lab, real projects.
Open to grads, postdocs, and undergrads. Financial aid available.
Apply: February 16, 2026
Reach out to @cmdonatelli.bsky.social @fishguy.bsky.social or @karlycohen.bsky.social with questions!
Details in the flyer ⬇️

Students had a blast at #SICB2026!

Come check out back-to-back Law lab talks today in the Shape and Climate session (room B112)!

10:15am - Long fuse evolution of carnivoran skeletal phenomes
13:30am - Endocranial shape variation in relation to climate in primates

#SICB2026 @sicb-dcb-dvm.bsky.social

Our reviewed preprint @elife.bsky.social: Brawn before bite in endemic Asian mammals after the end-Cretaceous extinction doi.org/10.7554/eLif...

The research team will undertake revisions based on the initial reviews to further strengthen the evidence underlying our work! #paleontology #mammals

Very excited for this incredible lineup of talks at #SSB2026!

ssb2026.github.io/talks.html

For those giving talks, more instructions will be sent shortly.

@systbiol.bsky.social

And here's a Q&A of the paper with @iampotassium.bsky.social

www.washington.edu/news/2025/12...

We are grateful to the staff and collections all these museums and support from NSF (DBI-2128146), a University of Texas Early Career Provost Fellowship, Paleontological Society, Burke Museum, & the European Research Council (ERC-2021-ADG).

We posit that climatic and environmental changes from the Eocene-Oligocene Transition facilitated skeletal diversification among carnivoran families, whereas changes from the Mid-Miocene Climate Transition 20 My later facilitated skeletal diversification within families.

🧵 6/n

We found nearly equal support for the two release and radiate models, where the evolution of skeletal phenomes transitions from a constrained adaptive zone under a Ornstein–Uhlenbeck process to skeletal diversification under Brownian motion at the EOT 34 Ma and at the MMCT 14 Ma.

🧵 5/n

We then tested 16 alternative hypotheses that could explain the disparity of carnivoran skeletal phenome by fitting a series of macroevolutionary models.

🧵 4/n

DTT revealed higher subclade disparity than expected during two time intervals. The 1st occurs 39-37 Ma, right between the Middle Eocene Climatic Optimum & the Eocene-Oligocene Transition (EOT). The 2nd occurs 14-1 Ma, coinciding with the end of the Mid-Miocene Climate Transition (MMCT).

🧵 3/n

We first quantified skeletal phenomes using 103 linear measurements from 118 extant species & 81 extinct species. We measured 854 specimens held at 17 museums!

🧵 2/n

Our manuscript is now out in @royalsocietypublishing.org! We tested hypotheses that Cenozoic climatic change influenced the evolution of the cranial, appendicular, & axial skeleton in carnivorans. @tsengzj.bsky.social @hlusko.bsky.social

🧵 1/n

royalsocietypublishing.org/rspb/article...

🧪🐠 I am hiring a postdoc! Work will be on patterns of biodiversity across phylogenetic scales using teleost fishes as a model. Apply by end of Jan 2026 for full consideration apply.interfolio.com/179070 I encourage folks to reach out with any questions. Please Share!

"NEST" logo for the Natural history Exploration Student Training Program. Logo contains a weasel inside a nest.

Finally made a logo and acronym for my mentorship program! Check it out chrisjlaw.github.io/NEST.html

Promoting the use of phylogenetic multinomial generalised mixed-effects model to understand the evolution of discrete traits Abstract. Phylogenetic comparative methods (PCMs) are fundamental tools for understanding trait evolution across species. While linear models are widely us

NEW METHODS ARTICLE: Phylogenetic GLMMs open doors to study evolution of discrete traits. We show how binary models extend to ordinal & nominal traits, using bird data, and provide tutorials to make these methods accessible to evolutionary biologists:

doi.org/10.1093/jeb/...
Mizuno et al.

Adaptive landscape and the evolution of flight in mammals

A big review of the evolution of bats:
www.annualreviews.org/content/jour...
🧪 ⚒️ #Paleobio #EvoBio

Wonder why this scene looks so familiar...
#WildlifeWednesday 🐦🐕

🚨 Recruiting 12 PhD students for a new NSF-funded program at the University of Alaska Fairbanks College of Fisheries and Ocean Sciences! This program is for U.S. students who received an Honorable Mention on the NSF GRFP within the last 3 years. @uafairbanks.bsky.social

www.uaf.edu/cfos/academi...

Collections Study Grants Collections study grants provide financial assistance for graduate students and post-doctoral researchers to study the collections of the University of Washington Burke Museum (UWBM).

New Collection Study Grants for students and postdocs to come visit the @burkemuseum.bsky.social! Applications due 12/15/25. www.burkemuseum.org/collections-...

Done

🦎THREAD: We just published something wild in @asn-amnat.bsky.social - lizards missing entire limbs not only survive, but some appear to actually thrive in the wild?!

Let me tell you about the "three-legged pirate" lizards 🏴‍☠️

[Paper: www.journals.uchicago.edu/doi/10.1086/... ]

(1/n)

Image of three brown and black fossil jaw fragments of extinct weasel relatives, Leptarctus, with short but sharp cusps. Open access paper at https://doi.org/10.5070/P9.48360

Celebrating #NationalFossilDay with a new paper describing specimens of the most whimsical of weasel relatives, leptarctine ("slender bear") mustelids, from the collections of @ucmpberkeley.bsky.social.

Their teeth are so much fun to look at! 🦷
doi.org/10.5070/P9.4...

(Cover image by P. Holroyd)