A fossil crustacean, discovered by a University of Leicester-led team of paleontologists, has been named Cascolus ravitis in honor of the naturalist and broadcaster Sir David Attenborough, in celebration of his 90th birthday.
Cascolus ravitis. Image credit: David J. Siveter et al.
Cascolus ravitis, a member of the stem-group of Leptostraca, is a distant relative of the living lobsters, shrimps and crabs.
This ancient crustacean lived during the Silurian period, approximately 430 million years ago.
University of Leicester Professor David Siveter, one of the paleontologists who made the discovery, said: “such a well-preserved fossil is exciting, and this particular one is a unique example of its kind in the fossil record, and so we can establish it as a new species of a new genus.”
Its scientific name honors Sir David Attenborough, who grew up on University College Leicester campus.
“Latin castrum ‘stronghold’ and colus ‘dwelling in’; alluding to the Middle/Old English source for the surname ‘Attenborough, derived from atten ‘at the’ and burgh ‘a fortified place.’ Latin Ratae, the Roman name for Leicester, vita ‘life’ and commeatis ‘a messenger’,” the researchers explained.
“In my youth, David Attenborough’s early programs on the BBC, such as ‘Zoo Quest,’ greatly encouraged my interest in Natural History and it is a pleasure to honor him in this way,” Prof. Siveter said.
“The biggest compliment that a biologist or paleontologist can pay to another one is to name a fossil in his honor and I take this as a very great compliment,” Sir David Attenborough said.
“I was once a scientist so I’m very honored and flattered that the Professor should say such nice things about me now.”
The find comes from volcanic ash deposits that accumulated in a marine setting in what is now Herefordshire in the Welsh Borderland, UK.
“The Herefordshire Konservat-Lagerstätte in the Welsh Borderland is globally important as a source of unparalleled paleobiological and phylogenetic data on a diversity of Mid-Silurian (430 million years ago) invertebrate animals,” Prof. Siveter and colleagues said.
“These include a brachiopod, a polychaete worm, aplacophorans, a gastropod, a stem-group asteroid, and most abundantly a range of arthropods comprising a stem-group euarthropod, a pycnogonid and other chelicerates, a marrellomorph, stem-group mandibulates, four ostracod species, a barnacle, a phyllocarid and a pentastomid.”
“The Herefordshire biota lived within the Welsh depositional basin, probably in a slope setting at water depths of 100–200 m,” they said.
“The remarkably preserved nature of Cascolus ravitis, with no sign of distortion even of the extremely fine flagella, suggests that, like other animals of the Lagerstätte, it was preserved rapidly in vivo.”
“Some 430 million years ago much of southern Britain was positioned in warm southerly subtropical latitudes, quite close to a large ancient continent of what we now call North America, and was covered by a shallow sea,” Prof. Siveter added.
“Cascolus ravitis and other animals living there died and were preserved when a fine volcanic ash rained down upon them.”
The new fossil is described as ‘exceptionally well preserved in three-dimensions’ — complete with the soft-parts of the animal, such as legs, eyes and very delicate antennae.
“Even though it is relatively small, at just 9 mm long, it preserves incredible detail including body parts that are normally not fossilized,” Prof. Siveter said.
“The cephalized post-antennulary appendages of Cascolus ravitis are clearly specialized for feeding and its gnathobases probably functioned to process and channel food to the mouth, although there is no obvious food groove. Like many of its arthropod faunal associates Cascolus ravitis may have been nektobenthic,” the scientists said.
“The large stalked eyes of Cascolus ravitis indicate an almost all-round field of view. As in most mandibulates the first head appendage of Cascolus ravitis probably functioned as a sensory receptor of environmental conditions.”
The research is published this week in the journal Proceedings of the Royal Society B.
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David J. Siveter et al. 2017. A new crustacean from the Herefordshire (Silurian) Lagerstätte, UK, and its significance in malacostracan evolution. Proc. R. Soc. B 284: 20170279; doi: 10.1098/rspb.2017.0279
