''Sphenofontis'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

sphenodontian 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 g ...

reptile known from the Late Jurassic of

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

, with a single known

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, ''S. velserae''. It is known from a single nearly complete and articulated sub-adult specimen (SNSB-BSPG 1993 XVIII 4), found in the late Kimmeridgian aged Torleite Formation in Brunn quarry in

Bavaria Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total lan ...

, Southern Germany. It is thought to be a close relative of the living

tuatara Tuatara (''Sphenodon punctatus'') are reptiles endemic to New Zealand. Despite their close resemblance to lizards, they are part of a distinct lineage, the order Rhynchocephalia. The name ''tuatara'' is derived from the Māori language and m ...

(''Sphenodon puncatus''), tentatively referred to Sphenodontinae.

Etymology

The genus name combines the prefix "Spheno-", with reference to the taxon being a sphenodontian, and the latin word "fontis"( spring, but also can mean "well"), roughly meaning “the sphenodontian of the well”. This acknowledges the origin of the name of the type locality Brunn, which comes from the German Brunnen (= well). The species name honours Lisa Velser, who discovered and prepared the holotype specimen.

Description

The holotype of ''Sphenofontis'' comprises a nearly complete and articulated skeleton of a subadult individual. ''Sphenofontis velserae'' can be diagnosed by at least three possible autapomorphies: a medially-displaced fourth additional tooth in the maxilla; proximally-constricted and strongly distally-expanded transverse processes of the first sacral vertebra; and anterolaterally-oriented transverse processes of the first caudal vertebra.

Paleobiology

''Sphenofontis'' does not display any evident specialization in its dentition, which was therefore most likely adapted to a generalist carnivorous/insectivorous diet comparable with that of the extant ''

Sphenodon Tuatara (''Sphenodon punctatus'') are reptiles endemic to New Zealand. Despite their close resemblance to lizards, they are part of a distinct lineage, the order Rhynchocephalia. The name ''tuatara'' is derived from the Māori language and m ...

''. The overall cranial and postcranial morphology lacks any clear adaptation towards an aquatic or semiaquatic mode of life, thus indicating that Sphenofontis lived in the terrestrial ecosystems of the islands. Based on limb and body proportions, ''Sphenofontis'' agrees more with ground-dwelling than arboreal habits in having rather short limbs when compared with the presacral length. Furthermore, it shows no indication of running abilities in the relative length of the limb elements. Thus, a less-specialized ground-dwelling behavior may be suggested for this new taxon. Its precise mode of life needs further morphofunctional studies to be better understood.

Paleoecology

''Sphenofontis'' lived in the Torleite Formation, which represents a sequence of Kimmeridgian deposits of an ancient archipelago.Torleite Formation
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.org In this environment, the

crocodylomorph Crocodylomorpha is a group of pseudosuchian archosaurs that includes the crocodilians and their extinct relatives. They were the only members of Pseudosuchia to survive the end-Triassic extinction. During Mesozoic and early Cenozoic times, cro ...

s '' Alligatorium'', '' Dakosaurus'' and ''

Cricosaurus ''Cricosaurus'' is an extinct genus of marine crocodyliforms of the Late Jurassic. belonging to the family Metriorhynchidae. The genus was established by Johann Andreas Wagner in 1858 for three skulls from the Tithonian (Late Jurassic) of German ...

'', the small theropod ''

Sciurumimus ''Sciurumimus'' ("Squirrel-mimic," named for its tail's resemblance to that of the tree squirrel, ''Sciurus'') is an extinct genus of tetanuran theropod from the Late Jurassic of Germany. It is known from a single juvenile specimen representing t ...

'', the

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tu ...

'' Eurysternum'' and a lot of fishes lived with ''Sphenofontis''.

References

Jurassic lepidosaurs Sphenodontia Fossil taxa described in 2021 {{Rhynchocephalia, state=autocollapse