''Judeasaurus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of small, aquatic varanoid lizard related to the

mosasaur Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and 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 Maastricht on ...

oids. The only known specimen is from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

of the

Middle East The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...

, though its exact provenance is uncertain.

Description

The specimen consists of an incomplete but partly articulated

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

and a number of cervical vertebrae exposed in

ventral 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 ...

view on a small slab of pink-grey limestone. The skull includes a fragmentary right

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. T ...

(with teeth), the co-ossified frontals and parietals, right

jugal The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species. Anatomy ...

, postorbitofrontals, supratemporals,

squamosal The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone. In most tetrapods, the squamosal and quadratojugal bones form the cheek series of the skull. The bone forms an ancestral co ...

s, quadrates, the right

dentary 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 teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

and fragmentary postdentary bones; the

occipital The occipital bone () is a cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occipital lobes of the cereb ...

region of the skull is hidden beneath a

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an ad ...

deposit. Some elements, such as the jugals, are preserved only as impressions. The skull is small, measuring only 60–70 millimeters in length.

History

There is some doubt surrounding the provenance of the

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 sever ...

and only known specimen (HUJI P4000, Hebrew University of Jerusalem), though it was likely recovered from the Judea Group, either from the upper Laminated Limestone Member of the Kefar Sha'ul Formation (Upper Cenomanian) or the lower member of the Bina Formation (Lower

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 b ...

), based on an examination of the lithology of the

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

matrix and planktonic

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

foraminifera Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly ...

preserved in the same slab.

Taxonomy and naming

The genus is named for the

Judean Hills The Judaean Mountains, or Judaean Hills ( he, הרי יהודה, translit=Harei Yehuda) or the Hebron Mountains ( ar, تلال الخليل, translit=Tilal al-Khalīl, links=, lit=Hebron Mountains), is a mountain range in Palestine and Israel wh ...

where the holotype of ''Judeasaurus tchernovi'' was discovered ("Judea lizard"), and the

etymology Etymology ()The New Oxford Dictionary of English (1998) – p. 633 "Etymology /ˌɛtɪˈmɒlədʒi/ the study of the class in words and the way their meanings have changed throughout time". is the study of the history of the Phonological chan ...

of the species name honours Eitan Tchernov for his contributions to the

paleontology Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...

. Haber and Polcyn (2005, p. 249) diagnose ''Judeasaurus tchernovi'' as a varanoid lizard: Haber and Polcyn (2005, 251-254) compare ''Judeasaurus'' with other marine varanoids (''Adriosaurus'' and ''Pontosaurus''), basal mosasauroids (including ''

Tethysaurus ''Tethysaurus'' is an extinct genus of tethysaurine mosasauroid from the Early Turonian (Late Cretaceous) period. The only species is ''Tethysaurus nopcsai''. Discovery The name means "Tethys' lizard of Nopcsa", a reference to the Greek godd ...

'', ''

Haasiasaurus ''Haasiasaurus'' is an extinct genus of early mosasaur, originally named "''Haasia''" by M. J. Polcyn ''et al.'', in honour of the palaeontologist Georg Haas (paleontologist), Georg Haas. (The original name was a junior homonym of ''Haasia'' Bol ...

'', and '' Halisaurus'') and with members of the paraphyletic Aigialosauridae, and determined that ''Judeasaurus'' "represents a new taxon within Varanoidea, related to mosasauroids based on its fused frontals and circular quadrate." An affiliation with another group of Late Cretaceous marine varanoids, the Dolichosauridae, is proposed but this relationship remains unresolved due to the poorly understood nature of dolichosaurs.

References

* Haber, A. et Polcyn, M. J. 2005. "A new marine varanoid from the Cenomanian of the Middle East." Netherlands Journal of Geosciences (Geologie en Mijnbouw) 84 (3):247-255. {{Taxonbar, from=Q3810972 Extinct animals of Asia Cretaceous lizards