503 million-year-old leanchoiliid arthropod (Alalcomenaeus sp.) from the Wheeler Formation in the House Range of Utah. Specimen collected by Valentin Jamart.
Rudy Lerosey-Aubril
@cambrianlife.bsky.social
🇪🇺🇺🇸Palaeontologist at @Harvard @HarvardOEB, investigating early animal life, especially arthropods 🕷️🐞🦂🦞🦐🐝.
Cambrian carrion fall? Here’s something I’ve been working on: a cluster of ~70 mid-Cambrian (500 Ma) fossils from the Wheeler Fm., Utah. It includes 54 individuals of the tiny trilobite Jenkinsonia varga, buried alive while likely feeding near a much larger decaying 🪱. Bon appétit !
Elrathia kingi is among the most famous trilobites. In the mid-Cambrian Wheeler Fm. (Utah), it reaches densities up to 500 individuals/m². Yet only one specimen associated with exceptional preservation (limbs) was hitherto known. Here is a second, preserving paired club-shaped gut glands.
Meet Megachelicerax cousteaui, a 500myo sea predator that just rewrote the evolutionary history of chelicerates by 20 million years! New study in @nature.com by @cambrianlife.bsky.social Dr. Rudy Lerosey-Aubril and Prof. Javier Ortega-Hernandez
A 500-million-year-old clawed predator rewrites the origin of spiders and horseshoe crabs
Harvard researchers reveal the earliest known Chelicerata in a new study published in Nature. The 500-million-year-old fossil, named Megachelicerax cousteaui, provides unequivocal evidence of chelicer...
eurekalert.org
Meet Megachelicerax, a Cambrian chelicerate - paper in @nature.com www.nature.com/articles/s41...
A chelicera-bearing arthropod reveals the Cambrian origin of chelicerates - Nature
Megachelicerax cousteaui gen. et sp. nov. is a large soft-bodied arthropod from the middle Cambrian of Utah featuring massive three-segmented chelicerae, along with five pairs of pseudobiramous prosom...
nature.com
I've been excited about this for days. Today we get a cool Cambrian critter that's the earliest known member of the group that contains spiders, scorpions, mites, and horseshoe crabs today. And its name? MEGACHELICERAX Read all about it in my latest newsletter.
The Mother of Spiders, Horseshoe Crabs, and Things That Go Snap
An exceptional fossil from Utah's west desert reveals pinching claws key to a major invertebrate family.
buttondown.com
A 500-million-year-old fossil of an early relative of spiders, scorpions, and mites offers insights into how this group of arthropods, called chelicerates, evolved. It has clear claws, and is among earliest known example of this feature in chelicerates: spklr.io/63329EysAT #Palaeontology
A chelicera-bearing arthropod reveals the Cambrian origin of chelicerates - Nature
Megachelicerax cousteaui gen. et sp. nov. is a large soft-bodied arthropod from the middle Cambrian of Utah featuring massive three-segmented chelicerae, along with five pairs of pseudobiramous prosomal limbs with non-foliaceous exopodal rami, and plate-like lamellae-bearing opisthosomal appendages.
spklr.io
Delighted to provide a News & Views for the new Cambrian chelicerate described by @cambrianlife.bsky.social & @invertebratepal.bsky.social in @nature.com www.nature.com/articles/d41... 🧪⚒️
Pincer movement: fossil pushes origins of chelicerate arthropods back to the Cambrian period
Spiders and scorpions belong to a group called chelicerates, which are arthropods with pincers at the front of their head. Fossil evidence reveals how this group evolved.
nature.com
#FossilFriday — 500 Ma bromance? The solute echinoderm Coleicarpus sprinklei (left) attached to Chancelloria eros (right). Wheeler Fm., House Range, Utah.
Some special locations preserve trilobite and arthropod soft tissue digestive systems. The gut tract is highlighted with the element phosphorus. @cambrianlife.bsky.social described the process in this open access paper: pmc.ncbi.nlm.nih.gov/articles/PMC... #12DaysofFossils
New Paper by Parry et al., reinterpreting the oldest diverse #jellyfish fauna as sessile polypoid dinomischids 🪼 These findings significantly expand the temporal and geographical range of dinomischids, elucidating their morphological and taphonomic variation. buff.ly/ERV7P3C #PaleoSky #Fossils
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Browse all journals
doi.org
🚨Deadline alert🚨 Just a few hours left to submit your abstract for GSA Connects 2025 (23:59 Pacific time TONIGHT!). If you want to present your latest paleontological, geochemical, sedimentological, or geobiological research on the Cambrian, session T155 is here for you!
Reminder: the abstract submission deadline for GSA Connects is rapidly approaching! If you'd like to contribute to our multidisciplinary session Evolution of Life in the Cambrian Seas, submit your abstract by 🚨Aug 5🚨. We're all super excited to hear about your latest research 🥸🤔🤠🤓!
Paleontologist to lead U.S. national academy | Science | AAAS www.science.org/content/arti...
Paleontologist to lead U.S. national academy
The prestigious organization faces funding challenges and political controversies
science.org
🚨Paper alert🚨 Permian bacteria fossilized as rod-shaped pyrite aggregates! A sweet taphonomy-oriented project led by L. Melim. If pyrite aggregates can similarly form in spherical bacteria, how could we distinguish them from extracellularly formed framboids 🤔🤔🤔 doi.org/10.2110/palo...
#FossilFriday Elrathia kingi is one of the most common trilobites in the Cambrian rocks of Utah’s West Desert. Thousands are found yearly—many geologists have one on their fridge. Yet this specimen - first published in 2008 - is the only one I know of that preserves both limbs and gut remains. 🤩
Enrolled Isotelus latus w dorsal pygidium broken away revealing classic isoteline "forked" #hypostome (ventral "mouth plate") disarticulated from cephalic doublure. Beautiful preservation of fingerprint-like #terrace ridges! #Ordovician (~450 MYA), Lindsay Fm, Colborne, #Ontario 🇨🇦 #TrilobiteTuesday
Another 🚨Paper alert🚨 Everything you ever wanted to know about colony development in graptolithine pterobranchs 🪸 Still much to uncover, but this sums up what we know so far. Enjoy, it is open access 😜 doi.org/10.1111/ede....
Reminder ⚠️ We are organizing a session at GSA Connects 2025 — T155: Evolution of Life in the Cambrian Seas — which aims to bring together paleontologists, sedimentologists, geochemists, and geobiologists working on this remarkable geological period. Submit your abstract by August 5❗
Many may not remember the DENDROGRAMMA mystery! This weird mushroom-shaped thing was described in 2014 as a "new metazoan" of unknown affinities! They were hinting that it might be a new phylum-but THEN 2 years later @drtimohara.bsky.social sequenced it and BOING! BENTHIC #SIPHONOPHORE!
Time for a long-overdue post—I've got lots to share lately! Let’s start with a 🚨paper alert 🚨: a great project on the Ediacaran tubicolous taxon Corumbella, masterfully led by @beckerkerber.bsky.social (🙏 thanks Bruno!). Takeaway: this tube was single-layered and round. doi.org/10.1098/rsos...
Rebuilding Earth’s first skeletal animals: the original morphology of Corumbella (Ediacaran, Brazil) | Royal Society Open Science
The evolutionary onset of animal biomineralization in the late Ediacaran (ca 555–538 Ma) is marked by the global appearance of enigmatic tubular fossils with unresolved phylogenetic relationships. Amo...
doi.org
🚨Conference alert🚨 L. Tarhan, R. Gaines, @invertebratepal.bsky.social and myself will co-chair session T155 - Evolution of Life in the Cambrian Seas at @geosociety.bsky.social GSA Connects 2025. Contact me if you have any questions about it. Deadline for abstract submission: August 5th.
Scientists first collected a pig butt worm from the dark ocean depths near Monterey, California. The size of marbles, pigbutts are a near complete mystery. Officially described in 2007, scientists aren’t even sure if the pigbutt form is an adult, or just a very very awkward adolescent stage.
As we wind down 2024, we've put together a list of the top #science stories of the year including a few familiar to @nhmu.bsky.social! Follow this link to read more: bit.ly/3DzCo1w
Top Science Stories of 2024
Here is our selection of the top science stories of the year.
nhmu.utah.edu
Using RAMAN to explore the preservation of soft-bodied fossils (here Cambrorhytium) from the mid Cambrian Gray Marjum site in Utah.
MASSIVELY excited to see Tityus achilles, South America's first #venom spraying #scorpion, finally described in @zoojlinnsoc.bsky.social ! This new species from #Colombia can spray venom at potential predators, a striking case of convergent #evolution 🧵 (1/n) academic.oup.com/zoolinnean/a...
For #FossilFriday have you ever considered the scorpion fossil record? This is surprisingly rich, but how we categorize these animals transcends being a hot mess. It's a spicy disaster. My colleague Jason and I wrote a paper on it which came out today: peerj.com/articles/185... ⚒️🧪🦀🦑 #evosky
Gills of lamprey ammocoete larvae, cephalochordates & the hemichordate enteropneust Saccoglossus are not for gas exchange. Instead, they function in ion regulation! Enteropneusts (="gut breathing") do not breathe from the gut. www.nature.com/articles/s41...
Ion regulation at gills precedes gas exchange and the origin of vertebrates - Nature
Measurements in three taxa with the characteristics of vertebrate ancestors (lamprey ammocoetes, amphioxus and acorn worms) suggest that gas exchange at gills has a vertebrate origin, b...
nature.com