Thililua is a genus

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 polycotylid

Polycotylidae

Polycotylidae is a family of plesiosaurs from the Cretaceous, a sister group to the Leptocleididae.With their short necks and large elongated heads, they resemble the pliosaurs, but closer phylogenetical studies indicate that they share many common features with the plesiosauridae and elasmosauridae...

 plesiosaur

Plesiosaur

Plesiosauroidea is an extinct clade of carnivorous plesiosaur marine reptiles. Plesiosauroids, are known from the Jurassic and Cretaceous Periods...

, containing one species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

, T. longicollis. The name Thililua is derived from that of an ancient aquatic god from local Berber

Berber people

Berbers are the indigenous peoples of North Africa west of the Nile Valley. They are continuously distributed from the Atlantic to the Siwa oasis, in Egypt, and from the Mediterranean to the Niger River. Historically they spoke the Berber language or varieties of it, which together form a branch...

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

Late Cretaceous

The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...

 (early Turonian

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 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...

) rocks in the High Atlas

High Atlas

High Atlas, also called the Grand Atlas Mountains is a mountain range in central Morocco in Northern Africa.The High Atlas rises in the west at the Atlantic Ocean and stretches in an eastern direction to the Moroccan-Algerian border. At the Atlantic and to the southwest the range drops abruptly...

 mountains of Morocco

Morocco

Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...

 in north Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

. Thililua is the first Polycotylid plesiosaur discovered in Africa, and also the first discovered that lived at a subtropical latitude. In 2010, Thililua was transferred to Leptocleididae

Leptocleididae

Leptocleididae is a family of small-sized plesiosaurs that lived during the Early Cretaceous period . Leptocleidus and Umoonasaurus had round bodies and triangle shaped heads. Hilary F. Ketchum and Roger B. J. Benson , transferred Brancasaurus, Kaiwhekea, Nichollssaura and Thililua to this family...

 as a sister taxon to Nichollssaura.

Anatomy

The type specimen of T. longicollis, which was described in 2003

2003 in paleontology

-New taxa:-Newly named dinosaurs:Data courtesy of George Olshevsky's dinosaur genera list and Dr. Jeremy Montague's dinosaur genus database.-New taxa:-New taxa:-Non-mammalian:-newly named:-Conifers:-Angiosperms:...

, consists of an almost complete skull

Skull

The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...

 and lower jaw, articulated with 37 vertebrae. Of these vertebrae, 30 were cervical (neck) vertebrae, which is an unusually high number compared to other Polycotylids, such as Dolichorhynchops

Dolichorhynchops

Dolichorhynchops is an extinct genus of polycotylid plesiosaur from the Late Cretaceous of North America, containing three species, D. osborni, D. herschelensis and D. tropicensis. Dolichorhynchops was an oceangoing prehistoric reptile...

, which had only 19 neck vertebrae, and Polycotylus

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-cupped vertebrae', referring to the shape of the vertebrae...

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

Cranial sutures

*Surgical suture, to describe stitches and other techniques for holding tissues together.* Geology, to describe a certain type of boundary between layers of rock....

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

Dolichorhynchops

Dolichorhynchops is an extinct genus of polycotylid plesiosaur from the Late Cretaceous of North America, containing three species, D. osborni, D. herschelensis and D. tropicensis. Dolichorhynchops was an oceangoing prehistoric reptile...

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