''Caviramus'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of caviramid

pterosaur Pterosaurs are 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 million to 66 million years ago). Pterosaurs are the earli ...

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 a ...

(early

Rhaetian The Rhaetian is the latest age (geology), age of the Triassic period (geology), Period (in geochronology) or the uppermost stage (stratigraphy), stage of the Triassic system (stratigraphy), System (in chronostratigraphy). It was preceded by the N ...

-age) lower Kössen Formation of the Northern Calcareous Alps of

Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...

. The genus was in 2006 named by Nadia Fröbisch and Jörg Fröbisch. The

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

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

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

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

Description

The genus is based on

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

PIMUZ A/III 1225, three non-contiguous fragments of a ramus (lower jaw) of the

mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

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

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

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''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hoove ...

covering. The jaw is light and hollow. The teeth of this genus resemble those of '' Eudimorphodon'', 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'', 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 mammals h ...

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

maxilla In vertebrates, the maxilla (: maxillae ) 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 two maxil ...

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 comminution, crushed and ground by the teeth. It is the first step in the process of digestion, allowing a greater surface area for digestive enzymes to break down the foods. During the mast ...

, 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 is a term used for a taxonomy (biology), 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 In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

of '' Carniadactylus'', 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, which in turn were within a clade he called Caviramidae.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, from1=Q19887990, from2=Q548702 Pterosaurs Rhaetian genera Late Triassic pterosaurs of Europe Fossil taxa described in 2006

Description

Lifestyle

Classification

See also

References