Nuthetes And Echinodon

''Nuthetes'' is the name given to a genus of theropod dinosaur, likely a dromaeosaurid, known only from fossil teeth and jaw fragments found in rocks of the middle Berriasian (Early Cretaceous) age in the Cherty Freshwater Member of the Lulworth Formation in England and also the Angeac-Charente bonebed in France. As a dromaeosaurid, ''Nuthetes'' would have been a small predator.

Discovery and naming

The holotype, DORCM G 913, was collected by Charles Willcox, an amateur paleontologist living at Swanage, from the Feather Quarry near Durlston Bay in a marine deposition of Cherty Freshwater Member of the Lulworth Formation, dating from the middle Berriasian. It consists of an about three inch long left dentary fragment with nine teeth. The holotype was once thought to be lost but was rediscovered in the seventies in the Dorset County Museum. Later several other teeth and specimen BMNH 48207, another dentary fragment from a somewhat smaller individual, were referred to the species. Owen in 1878 also assumed some fossilised scutes, of a type for which he coined the name "granicones", belonged to ''Nuthetes'' but these were in 2002 shown to be limb or tail osteoderms of a turtle, possibly ''" Helochelydra" anglica'' or ''"H." bakewelli''. In 2006 a tooth from France found at the Berriasian aged Cherves-de-Cognac locality, specimen CHEm03.537, was referred to a ''Nuthetes'' sp. Some large specimens referred to ''Nuthetes'' may instead belong to ''Dromaeosauroides''. Additional teeth have been attributed to ''Nuthetes'' from the nearby Angeac-Charente bonebed in western France.Ronan Allain, Romain Vullo, Lee Rozada, Jérémy Anquetin, Renaud Bourgeais, et al.
Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal turnover at the J/K boundary
Geodiversitas, Museum National d’Histoire Naturelle Paris, In press. ffhal-03264773f

The genus ''Nuthetes'' contains one species (the type species), ''Nuthetes destructor''. ''N. destructor'' was named and described by Richard Owen in 1854. The generic name ''Nuthetes'' is derived from the Koine Greek ''nouthetes'', a contraction of νουθέτητης (''nouthetetes'') meaning "one who admonishes" or "a monitor," in reference to the similarity of ''Nuthetes'' teeth to those of a modern monitor lizard. The specific name is Latin for "destroyer", a reference to "the adaptations of the teeth for piercing, cutting, and lacerating the prey" of a form he estimated to be equal in size to the present Bengal monitor.

Classification

''Nuthetes'' was originally classified by Owen as a lizard and a varanid; later he changed his mind concluding it was a crocodilian. Only in 1888 Richard Lydekker did understand it was a dinosaur. In 1934 William Elgin Swinton thought it was a juvenile member of the Megalosauridae. In 1970 Rodney Steel even renamed the species '' Megalosaurus destructor''. In 2002 however, a re-examination of the fossils by paleontologist Angela Milner showed that they most likely belonged to a subadult dromaeosaurid. Steve Sweetman examined five good specimens of fossil teeth and confirmed that they belong to ''Nuthetes destructor'', and concluded that this species is a velociraptorine dromaeosaurid. If this placement is correct, it would have been one of the oldest dromaeosaurids known, the first to be described, and the first known from Britain. However, Rauhut, Milner and Moore-Fay (2010) pointed out the great similarity of the teeth of basal tyrannosauroid '' Proceratosaurus'' to the teeth of velociraptorine dromaeosaurids. The authors recommended caution when referring to isolated teeth from the Late Jurassic or Early Cretaceous to the Dromaeosauridae (explicitly citing Milner's 2002 study and Sweetman's 2004 study as examples of studies that identified isolated theropod teeth as belonging to dromaeosaurids), as these teeth might belong to proceratosaurid tyrannosauroids instead.

According to Milner, ''Nuthetes'' can be diagnosed for having a tooth denticle size difference index ranging from 1-14 to 1-55.

See also

* Timeline of dromaeosaurid research

References

External links

Extensive description
from the Milner paper, on the Dinosaur Mailing List.

{{Taxonbar, from=Q957171

Early Cretaceous dinosaurs of Europe
Eudromaeosaurs
Fossil taxa described in 1854
Taxa named by Richard Owen