''Thililua'' 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 ...

polycotylid Polycotylidae is a family of plesiosaurs from the Cretaceous, a sister group to Leptocleididae. They are known as false pliosaurs. Polycotylids first appeared during the Albian stage of the Early Cretaceous, before becoming abundant and widesprea ...

plesiosaur The Plesiosauria or plesiosaurs are an Order (biology), order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period (geology), Period, possibly in the Rhaetian st ...

, containing one

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, ''T. longicollis''.

Discovery

The name ''Thililua'' is derived from that of an ancient aquatic god from local

Berber Berber or Berbers may refer to: Ethnic group * Berbers, an ethnic group native to Northern Africa * Berber languages, a family of Afro-Asiatic languages Places * Berber, Sudan, a town on the Nile People with the surname * Ady Berber (1913–196 ...

mythology; ''longicollis'' refers to the animal's long neck. ''Thililua'' has been found in

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent 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 ''cre ...

(early

Turonian The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...

) rocks in the

High Atlas The High Atlas, also called the Grand Atlas, is a mountain range in central Morocco, North Africa, the highest part of the Atlas Mountains. The High Atlas rises in the west at the Atlantic Ocean and stretches in an eastern direction to the Moro ...

mountains of

Morocco Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...

in north

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

. ''Thililua'' is the first Polycotylid plesiosaur discovered in Africa, and also the first discovered that lived at a

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

latitude. In 2010, ''Thililua'' was transferred to

Leptocleididae Leptocleididae is a family of small-sized plesiosaurs that lived during the Early Cretaceous period (early Berriasian to early Albian stage). They had small bodies with small heads and short necks. '' Leptocleidus'' and '' Umoonasaurus'' had roun ...

as a sister taxon to '' Nichollssaura''.

Description

The type specimen of ''T. longicollis'', which was described in

2003 2003 was designated by the United Nations as the International Year of Fresh water, Freshwater. In 2003, a Multi-National Force – Iraq, United States-led coalition 2003 invasion of Iraq, invaded Iraq, starting the Iraq War. Demographic ...

, consists of an almost complete

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

and

lower jaw 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 ...

, articulated with 37

vertebrae Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...

. Of these vertebrae, 30 were cervical (neck) vertebrae, which is an unusually high number compared to other Polycotylids, such as ''

Dolichorhynchops ''Dolichorhynchops'' is an extinct genus of polycotylid plesiosaur from the Late Cretaceous of North America, containing the species ''D. osborni'' and ''D. herschelensis'', with two previous species having been assigned to new genera. Definitiv ...

'', which had only 19 neck vertebrae, and ''

Polycotylus ''Polycotylus'' is a genus of plesiosaur within the family Polycotylidae. The type species is ''P. latippinis'' and was named by American paleontologist Edward Drinker Cope in 1869. Eleven other species have been identified. The name means 'much- ...

'', which had 26. It is believed to be an adult specimen, since some of the

cranial sutures In anatomy, fibrous joints are joints connected by Fibrous connective tissue, fibrous tissue, consisting mainly of collagen. These are fixed joints where bones are united by a layer of white fibrous tissue of varying thickness. In the skull, the ...

are very difficult to distinguish. Using comparisons with the head and neck length to body length ratio of a related genus, ''

'', the estimated total length of ''Thililua'' was 5.5 to 6 metres.

References

{{Taxonbar, from=Q16743868, from2=Q958323 Fossils of Morocco Late Cretaceous plesiosaurs Plesiosaurs of Africa Polycotylidae Fossil taxa described in 2003 Sauropterygian genera

Discovery

Description

See also

References