Our latest: Investigating the morphogenesis and replacement of lamprey toothlets using synchrotron imaging, led by Madleen Grohganz @bristolpalaeo.bsky.social, just out in Journal of Morphology. onlinelibrary.wiley.com/doi/epdf/10....

Do you like cichlids? Fossils? Fossil cichlids? Would you like to study them as part of a graduate degree at the University of Michigan, joining an NSF-funded project? Get in touch.

Last week I had my mind blown by the tenaculum, a fleshy club-like appendage growing out of a male ghost shark's forehead. The structure is studded with teeth and used to keep females close during mating. Latest for @nytimes.com explores the structure's evolution: www.nytimes.com/2025/09/06/s...

Excellent article on our latest ghost shark forehead "jaw" paper @pnas.org; written by @jack-tamisiea.bsky.social @nytimes.com - "Get to Know the Ratfish and the Forehead Teeth It Uses During Sex" 👻🦈🦷 @karlycohen.bsky.social @ufresearch.bsky.social www.nytimes.com/2025/09/06/s...

New preprint from some of my postdoc work on lungs! Co-led with Kaleb Hill, we studied smooth muscle and epithelial development in lizard lungs. Stay tuned for more! www.biorxiv.org/content/10.1...

Super excited to share our new paper, out today @pnas.org 'Teeth outside the jaw: Evolution and development of the toothed head clasper in chimaeras' @karlycohen.bsky.social 👻🦈 🦷 www.pnas.org/doi/10.1073/...

Excited to share our new paper by @danpaluh.bsky.social out today in @royalsociety.org Open Science; with a great team, including undergraduate researchers! "The metamorphic transition of the frog mouth: from tadpole kertanized mouthparts to adult teeth" 🦷🐸 royalsocietypublishing.org/doi/10.1098/...

Ever wondered how #sharks produce an unlimited supply of teeth? Our new preprint uncovers the genes within the dental stem cell niche driving lifelong tooth development. "Shark tooth regeneration: RNAseq reveals genes for unlimited dental renewal" 🦈🦷 bit.ly/47kkRHL

Our new paper is out in Royal Society Open Science! The metamorphic transition of the frog mouth: from tadpole keratinized mouthparts to adult teeth doi.org/10.1098/rsos...

Shark tooth regeneration: RNAseq reveals genes for unlimited dental renewal https://www.biorxiv.org/content/10.1101/2025.08.26.672487v1

Check out this "donut" Sandbar #Shark (Carcharhinidae) embryo in #3D, #VR or #AR via @sketchfab.bsky.social, photogrammetry by Kayla Evans @floridamuseum.bsky.social. This specimen is from a set of embryos with spinal deformations. @ufresearch.bsky.social skfb.ly/pAqxN

An article I wrote on the legacy of JAWS for the 50th anniversary was picked up by Australian Geographic! 🦈🦈 ausgeo.co/jaws

Here's a tortoise embryo developing inside its egg. Check out our new article in @cp-iscience.bsky.social to learn how molecular and mechanical systems sculpt their intricate head scales 🐢🧪 www.cell.com/iscience/ful...

First case of parthenogenesis in an intersexual zebra shark (Stegostoma tigrinum) having incomplete claspers onlinelibrary.wiley.com/doi/10.1111/...

In 1975, “Jaws” – the tale of a killer great white shark that terrorizes a coastal tourist town – captured people’s imaginations and simultaneously created a widespread fear of the water. (via @us.theconversation.com)

PBS News @pbsnews.org posted my article with @theconversation.com on the progress of shark science and the evolving perception of sharks since the release of 'JAWS', 50 years ago! 🦈🦈🦈 #jaws #jaws50 #sharks

50 years after ‘Jaws,’ researchers have retired the man-eater myth and revealed more about sharks’ amazing biology theconversation.com/50-years-aft...

The “Tooth Hurty” Joke Has Its Origins In Ancient, Armored Fish - defector.com/the-tooth-hu...

Cool shot of a super clear Catshark (Scyliorhinus canicula) egg. These shark egg cases vary in their transparency. This one is particularly see through. 🦈🦈🦈

Toothache may be hundreds of millions of years old. Teeth first evolved as sensory organs, not for chewing, according to a new analysis of animal fossils.

That look!! 👀 Our resident Bobcat came to visit this morning; captured on the backyard trail-cam! Such an awesome sight. I wonder if we'll have bob-kittens soon. 🐆 #bigcat #bobcat #backyardwildlife

The tooth, the whole tooth and nothing but the… frog? – the not-so bite-sized mystery of frog tooth re-evolution 🐸🦷 Check out this really fun post by @ryanharrison13.bsky.social, covering recent work from @danpaluh.bsky.social & team #preprint #preLight ⬇️ 👀 prelights.biologists.com/highlights/t...

New Pre-Print Alert! "Teeth Outside the Jaw: Evolution and Development of the Toothed Head Clasper in Chimaeras." We use fossil evidence, development and CT scans through ghost shark ontogeny to describe the emergence of the tenaculum! 👻🦈🦷 @karlycohen.bsky.social www.biorxiv.org/content/10.1...

🚨Registration for the UK #EvoDevo meeting is open! Join us on July 11th in London to enjoy an exciting day of talks, posters, friends, and superb science! -Registration (only £5!): shorturl.at/9cQGL -More info: londonevodevo.ac.uk

Exciting news! @wcratcliff.bsky.social and I published an essay last week in @nature.com reviewing the substantial contributions of 'long-term' studies to evolutionary biology www.nature.com/articles/s41... 1/n

#DBfeature 🦈🦷 Evolution, development, and regeneration of tooth-like epithelial appendages in sharks by Ella Nicklin, Gareth Fraser et al @ellanicklin.bsky.social @garethjfraser.bsky.social www.sciencedirect.com/science/arti...

Check out this "donut" shark! From the @floridamuseum.bsky.social - malformed embryos of the sandbar shark (Carcharhinus plumbeus). @ellanicklin.bsky.social CT scanned this specimen to show very odd development of the vertebral column, with no division of the centra and odd mineralization! 🍩🦈 #shark

Excited to share our new preprint, Tooth development in frogs: Implications for the re-evolution of lost mandibular teeth and the origin of a morphological innovation doi.org/10.1101/2025...

New preprint alert. Ever wondered why frogs only have upper jaw teeth? @danpaluh.bsky.social investigates this conundrum and asks if frogs ever form lower jaw tooth rudiments and what the relationship is between tadpole keratodonts (keratin mouthparts) and teeth! 🐸🦷🔥 www.biorxiv.org/content/10.1...

New NIH funded research from our group now out. We are interested in development and evolution of cell types and adult phenotypes. In this paper, postdoc Dylan Huang and collaborators asked how a pigmentary ornament of bright white cells develops on the fin of zebrafish. www.pnas.org/doi/10.1073/...

The many tooth generations of the zebra shark (Stegostoma tigrinum). Almost all of these teeth are made ahead of function. It's often hard to get your head around but I'm pretty sure they have too many teeth. And this is just the upper jaw of a juvenile! 🦈🦷🔥 #sharks #teeth

#Art in #Biology- ICB loves to celebrate #creative aspects of our author’s lives as well as their #science & in this vein, @garethjfraser.bsky.social shares with us "A Scientist's Life in Pictures". integrativeandcomparativebiology.wordpress.com/2025/02/18/a...

Glorious backyard trail-cam capture of a Bobcat (Lynx Rufus) at the creek. We don't see them too often. The trail-cam was set up on a short tripod and the result was an unexpected close-up! 🤩 #bobcat #backyardwildlife #floridawildlife

Our research made the cover of @nature.com 🎉! Read our article to learn how compressive forces sculpt the intricate head scales of crocodiles 🐊🧪 @lanevol.bsky.social @genevunige.bsky.social www.nature.com/articles/s41...

My first post! I just spent the morning free diving with grey nurse sharks aka sand tiger sharks (Carcharias taurus) at Bushrangers Bay, NSW. An incredible place to see these awesome but endangered animals. #sharks 🇦🇺

Check out our new #OA paper, part of EJLS' special issue "A Global Perspective on Adaptive Radiation"! With @aigverte.bsky.social & Marco Mello, we review the intrinsic & extrinsic factors potentially underlying the phyllostomid adaptive radiation 🦇https://doi.org/10.1093/evolinnean/kzae032

Come to Tokyo March 2026 for the limb conference! Honored to be sharing the keynote space with Cliff Tabin and Ken Poss.

Here's a model of the crocodile embryo's jaws, showing bone (light brown), dermis (pink), epidermis (red), collagen fibres (purple) and multisensory organs (orange). These features are essential for the mechanical patterning of their head scales 🐊 Learn more here ⬇️🧪 www.nature.com/articles/s41...

This is the upper jaw of a crocodile embryo, with nuclear staining in orange & proliferating cells in blue. This data helped us to build a mechanical simulation of crocodile head scale patterning. Learn more here ⬇️ 🧪 www.nature.com/articles/s41...

🚨Hyped to share our new article in @natureportfolio.bsky.social! We show that crocodile head scales develop from compressive folding that arises from constrained skin growth 🐊🔬 Really proud of this one - it's cool 😎 Please read & share! 🧪 @genevunige.bsky.social www.nature.com/articles/s41...