Paleontologists have unearthed fossilized teeth from a newly identified genus and species of plagioclase polyuria in the lower Cretaceous Luluworth Formation within the Purbeck Group in Dorset, England.

Multi-liquids represent a highly successful and diverse group of Mesozoic mammals.

Over 200 species have been documented, ranging in size from that of a mouse to a beaver.

These mammals thrived during the Central Jurassic throughout the Mesozoic Era, even surviving the mass extinction at the end of the Cretaceous, which led to the early, sparsely populated neural period.

They adapted to various ecological niches, from living in dens to climbing like squirrels.

The newly identified species existed during the Beliasia period in the pre-Cretaceous Epoch, around 143 million years ago.

Dubbing it Nova Cradon Mirabilis, this mammal was omnivorous, likely consuming small invertebrates like worms and insects.

Its sharp incisors and distinct, blade-like premolars demonstrate feeding strategies that differ from those of modern rodents such as squirrels and rats.

“This study illustrates how early mammals established their ecological roles while dinosaurs dominated the Earth,” remarked Professor David Martill from the University of Portsmouth and his colleagues.

The 1.65 cm jaw of Nova Cradon Mirabilis was discovered in 2024 by undergraduate Benjamin Weston at the University of Portsmouth.

“The fossil showcases long, pointed incisors at the front, followed by a gap and then four sharp premolars,” the paleontologist stated.

“While it superficially resembles a rabbit’s jaw, the pointed incisors and unique premolars clearly link it to the multi-iron group.”

The specimens were found at the upper beach area of Dalston Bay, Dorset, England.

This location is part of the Luluworth Formation from the Lower Cretaceous period of the Purbeck group.

“The new specimen is the most complete multi-iron structure found in the Purbeck group,” the researchers noted.

“The fossils were extracted from a distinctive layer in the so-called freshwater bed, specifically the flint bed, which scientists believe indicates deposition within freshwater lagoons.”

“Nova Cradon Mirabilis is also the first mammal recovered from the flint bed,” they added.

The discovery of Nova Cradon Mirabilis is detailed in a paper published in the Proceedings of the Geologists Association.

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Benjamin T. Weston et al. A new polyiron tube (mammal, Arosaria) from the Luluworth Formation (Cretaceous, Beliasian) in Dorset, England. Proceedings of the Geologists Association Published online on July 9, 2025. doi: 10.1016/j.pgeola.2025.101128