''Caviramus'' is a

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 ...

caviramid Caviramidae is a group of basal pterosaurs. It was erected by paleontologist Matthew G. Baron in 2020. It was defined as the least inclusive clade that includes '' Arcticodactylus cromptonellus'' and ''Caviramus schesaplanensis''. The members o ...

pterosaur Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to ...

from the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...

(early

Rhaetian The Rhaetian is the latest age of the Triassic Period (in geochronology) or the uppermost stage of the Triassic System (in chronostratigraphy). It was preceded by the Norian and succeeded by the Hettangian (the lowermost stage or earliest age ...

-age) lower

Kössen Formation The Kössen Formation is a Late Triassic (Rhaetian-age) geological formation in the Northern Calcareous Alps of Austria and Germany, in the Tiroler-Lech Nature Park. During the Late Triassic, the area now occupied by the Northern Calcareous Alps w ...

of the

Northern Calcareous Alps The Northern Limestone Alps (german: Nördliche Kalkalpen), also called the Northern Calcareous Alps, are the ranges of the Eastern Alps north of the Central Eastern Alps located in Austria and the adjacent Bavarian lands of southeastern Germany. ...

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

. The genus was in 2006 named by

Nadia Fröbisch Nadia Belinda Fröbisch (née Stöcker) is a German vertebrate paleontologist and developmental biologist who specializes in the evolution and development of amphibians. She is currently a professor at the Museum für Naturkunde Berlin in the Leibn ...

and Jörg Fröbisch. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

is ''Caviramus schesaplanensis''. The genus name is derived from

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

''cavus'', "hollow" and ''ramus'', "branch". The specific name refers to Mount

Schesaplana The Schesaplana is the highest mountain in the Rätikon mountain range at the border between Vorarlberg, Austria and Graubünden, Switzerland. It has an elevation of . On the north side of the Schesaplana is a glacier called '' Brandner Glet ...

Description

The genus is based on

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

PIMUZ A/III 1225, three non-contiguous fragments of a

ramus Ramus can refer to: * A branch (botany) * A portion of a bone (from Latin ''ramus'', "branch"), as in the Ramus of the mandible or Superior pubic ramus * A nerve ramus such as the Dorsal ramus of spinal nerve * A taxonomic rank ("branch" in English ...

(lower jaw) of the

mandible In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...

with multicuspate

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

. Two teeth are preserved, one with three cusps, and one with four; despite this difference the authors consider them as essentially isodont. The number of teeth is estimated at a minimum of twelve and a maximum of seventeen. A row of large oval

foramina In anatomy and osteology, a foramen (;Entry "foramen"
in

runs parallel to the tooth row; foramina in the form of small holes in the

anterior Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

part of the lower jaw suggest some sort of soft-tissue structure, or a

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...

covering. The jaw is light and hollow. The teeth of this genus resemble those of ''

Eudimorphodon ''Eudimorphodon'' was a pterosaur that was discovered in 1973 by Mario Pandolfi in the town of Cene, Italy and described the same year by Rocco Zambelli. The nearly complete skeleton was retrieved from shale deposited during the Late Triassic (mi ...

'', but the jaw is different. The discovery of this genus is a find of some significance, as there are few pterosaurs known from the Triassic. A second specimen, sometimes assigned to its own genus and species as ''

Raeticodactylus filisurensis ''Raeticodactylus'' is a genus of non-pterodactyloid pterosaur from the late Norian-early Rhaetian-age Upper Triassic lower Kössen Formation of the central Austroalpine of Grisons, Switzerland. It is known from holotype BNM 14524, a single dis ...

'', consists of a single disarticulated partial skeleton including an almost complete skull. The skull shows that it had a tall thin bony crest running along the midline of the front of the upper jaw, and a keel on the lower jaw. The teeth at the front of the upper jaw, in the

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has b ...

e, were fanglike, whereas the teeth in the upper cheeks (the

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

e) had three, four, or five cusps, similar to those of ''Eudimorphodon''. ''Caviramus'' had a wingspan of about 135 centimeters (53 in).

Lifestyle

Based on its long limbs, it might have been a terrestrial forager. It bears a dentition atypically suited for

mastication Chewing or mastication is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow a more efficient break down by enzymes. During the mastication process, th ...

, being more specialised to this than other eudimorphodonts, and may have been a generalist or herbivore. Its gracile wings suggested a soaring mode of flight.

Classification

Despite the resemblance to ''Eudimorphodon'' the authors classified ''Caviramus'' as Pterosauria ''

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

''. A 2009 study by Fabio Dalla Vecchia concluded that ''Raeticodactylus'', which is known from a more complete skeleton including lower jaw, probably belong to the same genus, and possibly the same species, if the differences (such as size and the presence of a crest in the ''Raeticodactylus'' specimen) are not due to sex or age. Subsequent studies have supported their synonymy. Dalla Vecchia found the two forms in a sister

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

of ''

Carniadactylus ''Carniadactylus'' is a genus of pterosaur which existed in Europe during the Late Triassic period (late Carnian or early Norian, about 228 million years agoBarrett, P. M., Butler, R. J., Edwards, N. P., & Milner, A. R. (2008). Pterosaur distribu ...

'', implying that ''Caviramus'' was a member of the Campylognathoididae The following phylogenetic analysis follows the topology of Upchurch ''et al.'' (2015). In 2020 however, a study upheld by Matthew G. Baron about early pterosaur interrelationships found ''Caviramus'' to group with ''Carniadactylus'', ''Raeticodactylus'', and the

Austriadraconidae Caviramidae is a group of basal pterosaurs. It was erected by paleontologist Matthew G. Baron in 2020. It was defined as the least inclusive clade that includes ''Arcticodactylus cromptonellus'' and ''Caviramus schesaplanensis''. The members of ...

, which in turn were within a clade he called

Caviramidae Caviramidae is a group of basal pterosaurs. It was erected by paleontologist Matthew G. Baron in 2020. It was defined as the least inclusive clade that includes '' Arcticodactylus cromptonellus'' and ''Caviramus schesaplanensis''. The members o ...

.Matthew G. Baron (2020). "Testing pterosaur ingroup relationships through broader sampling of avemetatarsalian taxa and characters and a range of phylogenetic analysis techniques". PeerJ. 8: e9604. doi:10.7717/peerj.9604. PMC 7512134. .

References

{{Taxonbar, from=Q548702 pterosaurs Rhaetian genera Late Triassic pterosaurs of Europe Fossil taxa described in 2006

Description

Lifestyle

Classification

See also

References