Caviramus
Encyclopedia
Caviramus is a genus
of "rhamphorhynchoid
" pterosaur
from the Late Triassic
(late Norian
-early Rhaetian
-age) lower Kössen Formation of the Northern Calcareous Alps
of Switzerland
.
The genus was in 2006 named by Nadia Fröbisch and Jörg Fröbisch. The type species
is Caviramus schesaplanensis. The genus name is derived from Latin
cavus, "hollow" and ramus, "branch". The specific name refers to Mount Schesaplana
.
PIMUZ A/III 1225, three non-contiguous fragments of a ramus
(lower jaw) of the mandible
with multicuspate teeth. 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
part of the lower jaw suggest some sort of soft-tissue structure, or a keratin
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, originally 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
e, were fanglike, whereas the teeth in the upper cheeks (the maxilla
e) had three, four, or five cusps, similar to those of Eudimorphodon. Caviramus had a wingspan of about 135 centimeters (53 in), and may have been a piscivore
, potentially a dip-feeder.
. 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
of Carniadactylus
, implying that Caviramus was a member of the Campylognathoididae
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of "rhamphorhynchoid
Rhamphorhynchoidea
The Rhamphorhynchoidea forms one of the two suborders of pterosaurs and represent an evolutionary grade of primitive members of this group of flying reptiles. This suborder is paraphyletic in relation to the Pterodactyloidea, which arose from within the Rhamphorhynchoidea, not from a more distant...
" pterosaur
Pterosaur
Pterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight...
from the Late Triassic
Late Triassic
The Late Triassic is in the geologic timescale the third and final of three epochs of the Triassic period. The corresponding series is known as the Upper Triassic. In the past it was sometimes called the Keuper, after a German lithostratigraphic group that has a roughly corresponding age...
(late Norian
Norian
The Norian is a division of the Triassic geological period. It has the rank of an age or stage . The Norian lasted from 216.5 ± 2.0 to 203.6 ± 1.5 million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.-Stratigraphic definitions:The Norian was named after the Noric Alps in...
-early Rhaetian
Rhaetian
The Rhaetian is in geochronology the latest age of the Triassic period or in chronostratigraphy the uppermost stage of the Triassic system. It lasted from 203.6 ± 1.5 to 199.6 ± 0.6 million years ago...
-age) lower Kössen Formation of the Northern Calcareous Alps
Northern Limestone Alps
The Northern Limestone 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. The distinction from the latter group, where the higher peaks are located, is based on differences in geological composition...
of Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
.
The genus was in 2006 named by Nadia Fröbisch and Jörg Fröbisch. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
is Caviramus schesaplanensis. The genus name is derived from Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
cavus, "hollow" and ramus, "branch". The specific name refers to Mount Schesaplana
Schesaplana
The Schesaplana is the highest mountain in the Rätikon mountain range at the border between Vorarlberg, Austria and Graubuenden, Switzerland. It has an elevation of ....
.
Description
The genus is based on holotypeHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
PIMUZ A/III 1225, three non-contiguous fragments of a ramus
Ramus
Ramus can refer to:* A branch* A portion of a bone , as in the Ramus of the mandible or Superior pubic ramus* A nerve ramus such as the Dorsal ramus of spinal nerve* Petrus Ramus...
(lower jaw) of the mandible
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
with multicuspate teeth. 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
Anatomical terms of location
Standard anatomical terms of location are designations employed in science that deal with the anatomy of animals to avoid ambiguities that might otherwise arise. They are not language-specific, and thus require no translation...
part of the lower jaw suggest some sort of soft-tissue structure, or a keratin
Keratin
Keratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails...
covering. The jaw is light and hollow. The teeth of this genus resemble those of Eudimorphodon
Eudimorphodon
Eudimorphodon was a pterosaur that was discovered in 1973 by Mario Pandolfi near Bergamo, Italy and described the same year by Rocco Zambelli. The nearly complete skeleton was retrieved from shale deposited during the Late Triassic , making Eudimorphodon the oldest pterosaur then known...
, 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, originally 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
Premaxilla
The incisive bone is the portion of the maxilla adjacent to the incisors. It is a pair of small cranial bones at the very tip of the jaws of many animals, usually bearing teeth, but not always. They are connected to the maxilla and the nasals....
e, were fanglike, whereas the teeth in the upper cheeks (the maxilla
Maxilla
The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...
e) had three, four, or five cusps, similar to those of Eudimorphodon. Caviramus had a wingspan of about 135 centimeters (53 in), and may have been a piscivore
Piscivore
A piscivore is a carnivorous animal which eats primarily fish. Piscivory was the diet of early tetrapods , insectivory came next, then in time reptiles added herbivory....
, potentially a dip-feeder.
Classification
Despite the resemblance to Eudimorphodon the authors classified Caviramus as Pterosauria incertae sedisIncertae sedis
, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...
. 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
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
of Carniadactylus
Carniadactylus
Carniadactylus is a genus of pterosaur which existed in Europe during the Late Triassic period. The genus contains a single species, Carniadactylus rosenfeldi.-Description:...
, implying that Caviramus was a member of the Campylognathoididae
Campylognathoididae
Campylognathoididae is a group of early "rhamphorhynchoid" pterosaurs named after Campylognathoides, that lived in the Late Jurassic. The family Campylognathoididae was named in 1967 by Oskar Kuhn, originally as the subfamily Campylognathoidinae....