''Chometokadmon'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

anguimorph The Anguimorpha is a suborder of squamates. The group was named by Fürbringer in 1900 to include all autarchoglossans closer to '' Varanus'' and ''Anguis'' than ''Scincus''. These lizards, along with iguanians and snakes, constitute the propos ...

lizard from the

Early Cretaceous The Early Cretaceous (geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pr ...

of Italy. The

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

and only species is ''Chometokadmon fitzingeri'', named by Italian zoologist

Oronzio Gabriele Costa Oronzo Gabriele Costa (26 August 1787, Alessano – 7 November 1867 Naples) was an Italian zoologist. At first a physician, he taught zoology at the University of Naples. He wrote 126 papers on various subjects, principally entomology, and in 18 ...

in 1864. It is known from only one specimen, a nearly complete skeleton from the comune of

Pietraroja Pietraroja is a mountain ''comune'' (municipality) in the province of Benevento in Campania, southern Italy. It is approximately 50 km by car from Benevento, in direction north-west, 83 km from Naples in direction north-east and appro ...

in the

Apennine Mountains The Apennines or Apennine Mountains (; grc-gre, links=no, Ἀπέννινα ὄρη or Ἀπέννινον ὄρος; la, Appenninus or – a singular with plural meaning;''Apenninus'' (Greek or ) has the form of an adjective, which wou ...

from the sediments of the Pietraroia Plattenkalk. Costa identified the specimen as a lizard, but in 1915 paleontologist

Geremia d'Erasmo Geremia and Geremias are surnames. Those bearing them include: 14-17th century * Geremia Ghisi, a Venetian nobleman who in ca. 1207 followed the Fourth Crusade * Geremia da Montagnone (died 1320/1321), Italian judge and author active in Padua ...

reclassified the skeleton as that of a

rhynchocephalia Rhynchocephalia (; ) is an order of lizard-like reptiles that includes only one living species, the tuatara (''Sphenodon punctatus'') of New Zealand. Despite its current lack of diversity, during the Mesozoic rhynchocephalians were a diverse gr ...

n on the basis of another rhynchocephalian specimen Costa had described, which d'Erasmo thought belonged to the same species. Later studies of the anatomy of these two specimens revealed that they belonged to two different species; Costa's ''Chometokadmon'' was a lizard whereas the other specimen, renamed ''

Derasmosaurus ''Derasmosaurus'' is an extinct species of rhynchocephalia Rhynchocephalia (; ) is an order of lizard-like reptiles that includes only one living species, the tuatara (''Sphenodon punctatus'') of New Zealand. Despite its current lack of div ...

'' in honor of d'Erasmo, was a rhynchocephalian. The first detailed description of ''Chometokadmon'' came in 2006, allowing it to be incorporated into a

phylogenetic analysis In biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that pro ...

of lizards. The analysis placed ''Chometokadmon'' as a member of the clade (evolutionary grouping) Anguimorpha, which includes

Anguidae Anguidae refers to a large and diverse family of lizards native to the Northern Hemisphere. Common characteristics of this group include a reduced supratemporal arch, striations on the medial faces of tooth crowns, osteoderms, and a lateral fold ...

Xenosauridae Xenosauridae is a family of anguimorph lizards whose only living representative is the genus ''Xenosaurus'', which is native to Central America. Xenosauridae also includes the extinct genera '' Exostinus'' and '' Restes''. Also known as knob-scal ...

, and

Varanoidea Varanoidea is a superfamily of lizards, including the well-known family Varanidae (the monitors and goannas). Also included in the Varanoidea are the Lanthanotidae ( earless monitor lizards), and the extinct Palaeovaranidae. Throughout their lo ...

References

Cretaceous lizards Early Cretaceous reptiles of Europe Fossil taxa described in 1864 Taxa named by Oronzio Gabriele Costa {{paleo-lizard-stub