Richard Dearden
@euphanerops.bsky.social
Fan of fossil fishes. Postdoc at University of Birmingham. Especially interested in using fossil and living taxa to understand the evolution of sharks, rays, and chimaeras. Also paint miniatures very slowly.
Excellent day out on the #2025SVP Warwickshire Triassic field trip to Guy's Cliffe! Feat. Saxon hermits, Anisian channel deposits, and lots of temnospondyls!
November 11, 2025 at 9:15 PM
Excellent day out on the #2025SVP Warwickshire Triassic field trip to Guy's Cliffe! Feat. Saxon hermits, Anisian channel deposits, and lots of temnospondyls!
Living sharks have innumerable tiny scales, but their earliest relatives somehow grew larger bony plates. In our new Biology Letters @royalsocietypublishing.org, we work try and out how, arguing they grew by fusing and remodelling spines and scales.
doi.org/10.1098/rsbl...
doi.org/10.1098/rsbl...
September 25, 2025 at 9:21 AM
Living sharks have innumerable tiny scales, but their earliest relatives somehow grew larger bony plates. In our new Biology Letters @royalsocietypublishing.org, we work try and out how, arguing they grew by fusing and remodelling spines and scales.
doi.org/10.1098/rsbl...
doi.org/10.1098/rsbl...
For #fossilfriday the toothplates of the LARGE Cretaceous elephant shark Edaphodon (L), from @sedgwickmuseum.bsky.social. Living elephant sharks (R) can get a little over a metre long, but Edaphodon's toothplates suggest it was elephantine in scale as well as trunkage, growing to over 3 metres! 🐘🦈
August 8, 2025 at 12:00 PM
For #fossilfriday the toothplates of the LARGE Cretaceous elephant shark Edaphodon (L), from @sedgwickmuseum.bsky.social. Living elephant sharks (R) can get a little over a metre long, but Edaphodon's toothplates suggest it was elephantine in scale as well as trunkage, growing to over 3 metres! 🐘🦈
(I say sorcerer but the real stars are the minions)
July 9, 2025 at 5:11 PM
(I say sorcerer but the real stars are the minions)
Finally finished a #Warhammer chaos sorcerer I've been chipping away at for ages! #miniatures
July 9, 2025 at 5:11 PM
Finally finished a #Warhammer chaos sorcerer I've been chipping away at for ages! #miniatures
For #FossilFriday Pararhincodon torquis: a new species of Cretaceous stem-group collared carpet shark we redescribed earlier this week based on CT data of skeletal fossils (see thread below).
Nice writeup on the @nhm-london.bsky.social website here
www.nhm.ac.uk/discover/new...
Nice writeup on the @nhm-london.bsky.social website here
www.nhm.ac.uk/discover/new...
May 2, 2025 at 4:10 PM
For #FossilFriday Pararhincodon torquis: a new species of Cretaceous stem-group collared carpet shark we redescribed earlier this week based on CT data of skeletal fossils (see thread below).
Nice writeup on the @nhm-london.bsky.social website here
www.nhm.ac.uk/discover/new...
Nice writeup on the @nhm-london.bsky.social website here
www.nhm.ac.uk/discover/new...
Huge thanks to all co-authors for their contributions, without which this sharky detective work would have come to naught. Thanks to Martin Rücklin @naturalis.bsky.social who hosted me, the @ec.europa.eu #MSCA for funding, and @nhm-london.bsky.social for specimens (and prep permission!)
(13/13)
(13/13)
April 30, 2025 at 1:23 PM
Huge thanks to all co-authors for their contributions, without which this sharky detective work would have come to naught. Thanks to Martin Rücklin @naturalis.bsky.social who hosted me, the @ec.europa.eu #MSCA for funding, and @nhm-london.bsky.social for specimens (and prep permission!)
(13/13)
(13/13)
More generally this shows the Chalk's potential as a repository of 3D fossil sharks which can explicitly tie the tooth record to gross anatomy and spans the gap between the earliest crown-group sharks from the Jurassic and Cenozoic ones. More 3D Chalk sharks exist so hopefully more to come!
(11/13)
(11/13)
April 30, 2025 at 1:23 PM
More generally this shows the Chalk's potential as a repository of 3D fossil sharks which can explicitly tie the tooth record to gross anatomy and spans the gap between the earliest crown-group sharks from the Jurassic and Cenozoic ones. More 3D Chalk sharks exist so hopefully more to come!
(11/13)
(11/13)
Fossil teeth show that carpet sharks moved from what is now the Chalk to their modern Indo-Pacific hotspot via the Tethys. Our data shows parascylliids had locked in some of their strange anatomy (e.g. braincase) before they split but aspects like weird pectoral fins had yet to evolve.
(10/13)
(10/13)
April 30, 2025 at 1:23 PM
Fossil teeth show that carpet sharks moved from what is now the Chalk to their modern Indo-Pacific hotspot via the Tethys. Our data shows parascylliids had locked in some of their strange anatomy (e.g. braincase) before they split but aspects like weird pectoral fins had yet to evolve.
(10/13)
(10/13)
We named this new species Pararhincodon torquis n. sp. Pararhincodon = "near-whale shark". Our species name is for the torc, a collar associated with the European iron age, tying things back to collared carpet sharks. @lacerdajulio.bsky.social did a lovely reconstruction for us feat. collar!
(9/13)
(9/13)
April 30, 2025 at 1:23 PM
We named this new species Pararhincodon torquis n. sp. Pararhincodon = "near-whale shark". Our species name is for the torc, a collar associated with the European iron age, tying things back to collared carpet sharks. @lacerdajulio.bsky.social did a lovely reconstruction for us feat. collar!
(9/13)
(9/13)
These teeth can be attributed to a new species of the extinct genus Pararhincodon. Pararhincodon was thought, tentatively, to be a parascylliid based on a single published, articulated Lebanese specimen. We show conclusively that it is a stem-group parascyllid based on skeletal characters.
(8/13)
(8/13)
April 30, 2025 at 1:23 PM
These teeth can be attributed to a new species of the extinct genus Pararhincodon. Pararhincodon was thought, tentatively, to be a parascylliid based on a single published, articulated Lebanese specimen. We show conclusively that it is a stem-group parascyllid based on skeletal characters.
(8/13)
(8/13)
Rough models of the teeth and helpful colleagues gave us clues as to what these teeth could be. To be sure though we needed high-resolution data. Incredibly, co-author Kieran Miles was able to extract one specific tooth from each specimen, located in the CT data, allowing us to SEM them
(7/13)
(7/13)
April 30, 2025 at 1:23 PM
Rough models of the teeth and helpful colleagues gave us clues as to what these teeth could be. To be sure though we needed high-resolution data. Incredibly, co-author Kieran Miles was able to extract one specific tooth from each specimen, located in the CT data, allowing us to SEM them
(7/13)
(7/13)
But what about those missing teeth? After looking more closely at the scan data we realised that teeth were there in both specimens: they were just tiny (1-2mm across) and scattered amongst the very similar-looking dermal denticles in the Chalk matrix (small white things in video below).
(6/13)
(6/13)
April 30, 2025 at 1:23 PM
But what about those missing teeth? After looking more closely at the scan data we realised that teeth were there in both specimens: they were just tiny (1-2mm across) and scattered amongst the very similar-looking dermal denticles in the Chalk matrix (small white things in video below).
(6/13)
(6/13)
Skeletal detective work led us to collared carpet sharks (parascylliids): small, beautifully patterned, eel-like sharks from Australia/Indo-Pacific. CSIRO colleagues (inc. co-author Helen O'Neill) helpfully scanned an extant one, confirming these had the same weirdly-shaped braincase.
(5/13)
(5/13)
April 30, 2025 at 1:23 PM
Skeletal detective work led us to collared carpet sharks (parascylliids): small, beautifully patterned, eel-like sharks from Australia/Indo-Pacific. CSIRO colleagues (inc. co-author Helen O'Neill) helpfully scanned an extant one, confirming these had the same weirdly-shaped braincase.
(5/13)
(5/13)
Around this time we found a second Chalk specimen, @nhm-london.bsky.social, this time labelled even less informatively "Chondrichthyes" (i.e. sharks + friends). CT showed this rather unpromising fossil had the same weird braincase, and preserved the whole body back to the pectoral fins.
(4/13)
(4/13)
April 30, 2025 at 1:23 PM
Around this time we found a second Chalk specimen, @nhm-london.bsky.social, this time labelled even less informatively "Chondrichthyes" (i.e. sharks + friends). CT showed this rather unpromising fossil had the same weird braincase, and preserved the whole body back to the pectoral fins.
(4/13)
(4/13)
Dear reader, we did not find out what Synechodus looked like, with it swiftly becoming clear this this thing looked nothing like Synechodus. It had a strangely-shaped braincase, the jaws were different and there was no sign of any teeth, Synechodus-like or otherwise. So what was it?
(3/13)
(3/13)
April 30, 2025 at 1:23 PM
Dear reader, we did not find out what Synechodus looked like, with it swiftly becoming clear this this thing looked nothing like Synechodus. It had a strangely-shaped braincase, the jaws were different and there was no sign of any teeth, Synechodus-like or otherwise. So what was it?
(3/13)
(3/13)
This project spun off another project, redescribing extinct Chalk shark Synechodus. This @nhm-london.bsky.social specimen below, was labelled "Synechodus sp.", despite no teeth being visible. Fool that I was, I believed the label and we CT scanned it to find out what Synechodus looked like.
(2/13)
(2/13)
April 30, 2025 at 1:23 PM
This project spun off another project, redescribing extinct Chalk shark Synechodus. This @nhm-london.bsky.social specimen below, was labelled "Synechodus sp.", despite no teeth being visible. Fool that I was, I believed the label and we CT scanned it to find out what Synechodus looked like.
(2/13)
(2/13)
New #OA paper in @royalsocietypublishing.org #RSOS: we use CT to describe a 3D shark from the Cretaceous Chalk, giving a rare skeletal perspective on shark evolution.
A bit of the backstory in 🧵below featuring
🦴 MYSTERY FOSSILS
🦈 CUTE SHARKS
🦷 CHALK DENTISTRY
doi.org/10.1098/rsos...
(1/13)
A bit of the backstory in 🧵below featuring
🦴 MYSTERY FOSSILS
🦈 CUTE SHARKS
🦷 CHALK DENTISTRY
doi.org/10.1098/rsos...
(1/13)
April 30, 2025 at 1:23 PM
New #OA paper in @royalsocietypublishing.org #RSOS: we use CT to describe a 3D shark from the Cretaceous Chalk, giving a rare skeletal perspective on shark evolution.
A bit of the backstory in 🧵below featuring
🦴 MYSTERY FOSSILS
🦈 CUTE SHARKS
🦷 CHALK DENTISTRY
doi.org/10.1098/rsos...
(1/13)
A bit of the backstory in 🧵below featuring
🦴 MYSTERY FOSSILS
🦈 CUTE SHARKS
🦷 CHALK DENTISTRY
doi.org/10.1098/rsos...
(1/13)
Like fossil #sharks? Check out our new preprint from work @naturalis.bsky.social where we combine digital/hands on approaches with fossil/extant taxa to describe the 3D skeletal anatomy of Cretaceous collared carpet sharks from the English Chalk. Paper out soon, thanks to all collaborators! 🦈
March 18, 2025 at 10:50 AM
Like fossil #sharks? Check out our new preprint from work @naturalis.bsky.social where we combine digital/hands on approaches with fossil/extant taxa to describe the 3D skeletal anatomy of Cretaceous collared carpet sharks from the English Chalk. Paper out soon, thanks to all collaborators! 🦈
Sadly Ischyodus lost its nose: here's the full picture
December 13, 2024 at 7:56 PM
Sadly Ischyodus lost its nose: here's the full picture
Had an amazing time at #PalAss24: Awesome job by the organisers @rachelwarnock.bsky.social, @taphonomist.bsky.social and @emmadnn.bsky.social, as well as all volunteers! For #fossilfriday some lovely Jurassic chondrichthyans from Solnhofen I saw on the preconference fieldtrip
December 13, 2024 at 7:54 PM
Had an amazing time at #PalAss24: Awesome job by the organisers @rachelwarnock.bsky.social, @taphonomist.bsky.social and @emmadnn.bsky.social, as well as all volunteers! For #fossilfriday some lovely Jurassic chondrichthyans from Solnhofen I saw on the preconference fieldtrip
Sad #FossilFriday as it's my last day as a postdoc at @naturalis.bsky.social. In tribute here are four excellent fossil fishes I got to see while doing my research here.
November 29, 2024 at 1:37 PM
Sad #FossilFriday as it's my last day as a postdoc at @naturalis.bsky.social. In tribute here are four excellent fossil fishes I got to see while doing my research here.
Nose-on view of Devonian long boi Elpistostege, a stem-group tetrapod from the Escuminac Formation, Quebec. Amazing fossil and beautiful reconstruction . #fossilfriday
November 15, 2024 at 9:56 AM
Nose-on view of Devonian long boi Elpistostege, a stem-group tetrapod from the Escuminac Formation, Quebec. Amazing fossil and beautiful reconstruction . #fossilfriday
Happy International Ghost Shark day to all those who celebrate! 👻🦈 Check out our new, well-timed paper in Proceedings B, led by @chasebrownstein.bsky.social, combining fossils and genes to understand how and when they invaded the deep sea.
doi.org/10.1098/rspb...
doi.org/10.1098/rspb...
October 30, 2024 at 7:05 PM
Happy International Ghost Shark day to all those who celebrate! 👻🦈 Check out our new, well-timed paper in Proceedings B, led by @chasebrownstein.bsky.social, combining fossils and genes to understand how and when they invaded the deep sea.
doi.org/10.1098/rspb...
doi.org/10.1098/rspb...