''Tethysaurus'' 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 ...
of
tethysaurine
The Tethysaurinae are a subfamily of mosasaurs, a diverse group of Late Cretaceous marine squamates. Members of the subfamily are informally and collectively known as "tethysaurines" and have been recovered from North America and Africa. Only two ...
mosasauroid
Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Ancient Greek, Greek ' meaning 'lizard') comprise a group of extinct, large marine reptiles from the Late Cretaceous. Their first fossil remains were discovered in a limestone quarry at Ma ...
from the Early
Turonian
The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded by t ...
(Late Cretaceous) period. The only species is ''Tethysaurus nopcsai''.
Discovery
![Tethysaurus nopcsai 45](https://upload.wikimedia.org/wikipedia/commons/e/ea/Tethysaurus_nopcsai_45.JPG)
The name means "Tethys' lizard of Nopcsa", a reference to the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
goddess
A goddess is a female deity. In many known cultures, goddesses are often linked with literal or metaphorical pregnancy or imagined feminine roles associated with how women and girls are perceived or expected to behave. This includes themes of s ...
of the sea
Tethys (also the name of the
Tethys Ocean
The Tethys Ocean ( el, Τηθύς ''Tēthús''), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean that covered most of the Earth during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents ...
, an ancient sea between southern Europe and northern Africa) and to the
Hungarian paleontologist
Baron
Baron is a rank of nobility or title of honour, often hereditary, in various European countries, either current or historical. The female equivalent is baroness. Typically, the title denotes an aristocrat who ranks higher than a lord or knig ...
Ferenc Nopcsa, who made pioneering studies on
Adriatic
The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkans, Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) ...
aquatic
squamate
Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest order of reptiles, comprising lizards, snakes, and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles. With over 10,900 species, ...
s. It was found in the
Akrabou Formation, near the villages of Tadirhourst and Asfla in the region of
Goulmima
Goulmima () is a town in Morocco situated in the province of Errachidia, in the region of Drâa-Tafilalet. An agricultural oasis, it is fed by the Wadi Gheris from the central High Atlas mountains. Like other settlements in Tafilalet, it was bu ...
,
Errachidia Province
Errachidia (Berber language: Imetɣaren) is a province located in eastern central Morocco in the region of Dra-Tafilalt.
Errachidia is bordered by Algeria to the southeast and by the Moroccan provinces of Figig to the northeast, Midelt to the no ...
, in
Morocco
Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...
, with three referred specimens that included a nearly complete articulated skull, mandible,
vertebra
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...
e and portions of the
appendicular skeleton
The appendicular skeleton is the portion of the skeleton of vertebrates consisting of the bones that support the appendages. There are 126 bones. The appendicular skeleton includes the skeletal elements within the limbs, as well as supporting shou ...
. The diagnosis after Bardet ''et al''. is "(...) prefrontal strongly vaulted in anterior view; parietal exhibits a triangular table ending posteriorly in two pointed pegs overlying the supraoccipital; jugal with a large and wide ascending ramus; medullar floor of the basioccipital pierced by three foramina; splenial with a large notched dorsomedial process; surangular exposed medially ventral to the coronoid; dental formula: 19-20 maxillary, 15-19 pterygoid and at least 19 dentary teeth; large paracotylar and parazygosphenal
on vertebrae."
[
]
Description
An average-sized mosasaur measuring long and weighing ,[ ''Tethysaurus'' displays a number of basal and ]derived
Derive may refer to:
* Derive (computer algebra system), a commercial system made by Texas Instruments
* ''Dérive'' (magazine), an Austrian science magazine on urbanism
*Dérive, a psychogeographical concept
See also
*
*Derivation (disambiguatio ...
features that led to an initial classification as an intermediate stage between primitive aigialosaurids of the Cenomanian
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...
and derived mosasaurids from the Turonian to the Maastrichtian
The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...
. More recent analysis put ''Tethysaurus'' in a 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, ...
along ''Russellosaurus
''Russellosaurus'' is an extinct genus of tethysaurine mosasauroid from the Late Cretaceous of North America. The genus was described from a skull discovered in an exposure of the Arcadia Park Shale (lower Middle Turonian) at Cedar Hill, Dallas ...
'' and ''Yaguarasaurus
''Yaguarasaurus'' is an extinct genus of mosasauroid from the Late Cretaceous (Turonian) period of Colombia, South America. The remains discovered (an articulated skull, some vertebrae and ribs) were defined as a new genus and species of mosasaur ...
'' called the parafamily Russellosaurina, as a basal Turonian clade of Mosasauridae.
Phylogeny
Cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...
based in the analysis by Makádi ''et al.'' in 2012:
See also
* List of mosasaurs
This list of mosasaurs is a comprehensive listing of all genera that have ever been included in the family Mosasauridae or the parent clade Mosasauroidea, excluding purely vernacular terms. The list includes all commonly accepted genera, but als ...
References
External links
Oceans of Kansas
Paleobiology Database: Tethysaurus
Russellosaurins
Mosasaurs of Africa
Fossil taxa described in 2003
{{paleo-lizard-stub