Halisaurus ("Ocean Lizard") is an extinct genus of marine lizard belonging to the mosasaur family. With a length of 3–4 m (10–13 ft), it was small compared to most other mosasaurs. It was named by Othniel Charles Marsh in 1869, but renamed Baptosaurus by Marsh in 1870, who thought the name was already in use (preoccupied) by a fish named Halosaurus. According to modern rules, a difference of a letter is enough and the substitute name is unneeded.

 Halisaurinae  is a subfamily of mosasaurs, a diverse group of Late Cretaceous marine squamates.

 Bardet et al. (2005, p. 464) diagnosed the Halsaurinae as all mosasaurs more closely related to Halisaurus than Moanasaurus. Unambiguous character states were listed as follows: "premaxilla-maxilla sutural contact vertical anteriorly, oblique at midpoint and horizontal posteriorly; contact plane between the parietal and the supratemporal oblique; preaxial ridge extending on two-thirds of the length of the radius; tibia and fibula long and slender with slightly expanded extremities. Ambiguous characters include "dorsal median ridge borne on the anterior two-thirds of the frontal; frontal with ventral boss; parietal foramen surrounded by a ventral boss; quadrate with large infrastapedial process; coalescent infra- and suprastapedial processes of quadrate; zygosphene-zygantrum complex absent; synapophyses of the cervical vertebrae extending ventrally to the ventral surface of the centrum; fused haemal spines."

 Designation of this subfamily followed many decades of confusion surrounding the type genus, Halisaurus, especially H. sternbergii, a species from the Mooreville Chalk Formation of Alabama and the Niobrara Chalk of Kansas. Originally, the species had been referred to the mosasaurine Clidastes, then to Halisaurus (Russell, 1967; p. 369 ), which was also considered a member of the Mosasaurinae at that time. Later workers  questioned the phylogenetic position and monophyly of Halisaurus, in part because of striking morphological differences between H. sternbergii and the other known species of the taxon. Finally, Bardet et al. (2004) determined that H. sternbergii was not conspecific with the other members of the genus and erected a new genus, Eonatator, as well a new subfamily, consisting of Eonatator and Halisaurus. Halisaurines (as members of this subfamily are collectively and informally known) were small to medium-sized mosasaurs averaging 4,5 - 6+ meters in length. Of all known mosasaurids, they were the least adapted to a marine lifestyle. Halisaurines are known from North America, Europe, South America, and Africa. The earliest known remains of halisaurines occur in rocks of Santonian age and the subfamily persists until the latest Maastrichtian. The etymology of this group derives from the genus Halisaurus (Greek halis = "sea" + Greek sauros = "lizard").

 Мозазавры (Mosasauridae) — вымершее семейство ящериц (Lacertilia). Близкие родственники современных варанов. Мозазавры были приспособлены к обитанию в водной среде: тело имело обтекаемую форму, а конечности были преобразованы в ласты. Существовали в меловом периоде. Останки обнаружены на всех континентах, включая Антарктиду.

 Предположительный предок мозазавров найден в отложениях нижнего мела Японии. В его качестве рассматривают мелкую водную ящерицу каганаиас (Kaganaias), обладавшую телом змеевидной формы и короткими конечностями.

 Длина мозазавров колеблется от 3 м до 17 м. Самые крупные представители мозазавридов — тилозавр (15—25 м), гайнозавр и мозазавр (оба до 17 м).

 Мозазавры заняли многие экологические ниши в морях мелового периода. Главным образом это были ниши хищников крупных и средних размеров. Но некоторые виды, как например глобиденс (Globidens), зубы которого были шаровидной, удобной для раскусывания раковин моллюсков формы, освоили ниши «моллюскоедов».

 Halisaurus arambourgi — вид, живший в конце мелового периода около 70-65 млн лет назад на территории современного Марокко.

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Tags: Вымершие рептилии, Мел, варанообразные, диапсиды, лепидозавроморфы, лепидозавры, мозазавриды, мозазавроиды, хализавры, чешуйчатые, ящерицы

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