Orinoco crocodileThe Orinoco crocodile (Crocodylus intermedius) is a critically endangered crocodile. Its population is very small, and they can only be found in the Orinoco river basin in Venezuela and Colombia. Extensively hunted for their skins in the 19th and 20th centuries, it is one of the most endangered species of crocodiles. It is a very large species of crocodilian; males have been reported up to in the past, weighing over , but such sizes do not exist today, being a more widely accepted maximum size.
GavialisGavialis is a genus of crocodylians that includes the living gharial Gavialis gangeticus and one known extinct species, Gavialis bengawanicus. G. gangeticus comes from the Indian Subcontinent, while G. bengawanicus is known from Java. Gavialis likely first appeared in the Indian Subcontinent in the Pliocene and dispersed into the Malay Archipelago through a path called the Siva–Malayan route in the Quaternary.
AlligatoroideaAlligatoroidea is one of three superfamilies of crocodylians, the other two being Crocodyloidea and Gavialoidea. Alligatoroidea evolved in the Late Cretaceous period, and consists of the alligators and caimans, as well as extinct members more closely related to the alligators than the two other groups. The superfamily Alligatoroidea is thought to have split from the crocodile-gharial lineage in the late Cretaceous, about 80 million years ago, but possibly as early as 100 million years ago based on molecular phylogenetics.
Crown groupIn phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. It is thus a way of defining a clade, a group consisting of a species and all its extant or extinct descendants. For example, Neornithes (birds) can be defined as a crown group, which includes the most recent common ancestor of all modern birds, and all of its extant or extinct descendants.
Morelet's crocodileMorelet's crocodile (Crocodylus moreletii), also known as the Mexican crocodile or Belize crocodile, is a modest-sized crocodilian found only in fresh waters of the Atlantic regions of Mexico, Belize and Guatemala. It usually grows to about in length. It is a Least Concern species. The species has a fossil record in Guatemala. Morelet's crocodile was first described in 1850 in Mexico by the French naturalist Pierre Marie Arthur Morelet. The species was subsequently named after him.
PterosaurPterosaurs (ˈtɛrəsɔr,_ˈtɛroʊ-; from Greek pteron and sauros, meaning "wing lizard") are an extinct clade of flying reptiles in the order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to 66 million years ago). Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger.
Siamese crocodileThe Siamese crocodile (Crocodylus siamensis) is a medium-sized freshwater crocodile native to Indonesia (Borneo and possibly Java), Brunei, East Malaysia, Laos, Cambodia, Myanmar, Thailand and Vietnam. The species is critically endangered and already extirpated from many regions. Its other common names include Siamese freshwater crocodile, Singapore small-grain, and soft-belly. Below is a cladogram based on a 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data, as revised by the 2021 Hekkala et al.
Cuban crocodileThe Cuban crocodile (Crocodylus rhombifer) is a small-medium species of crocodile endemic to Cuba. Typical length is and typical weight . Large males can reach as much as in length and weigh more than . Despite its smaller size, it is a highly aggressive animal (one of the most territorial of all crocodilians), and potentially dangerous to humans. The Cuban crocodile is of interest to biologists, for its unique physical and behavioral traits. Long- and strong-legged, it is the most terrestrial of extant crocodiles.
Scale (anatomy)In most biological nomenclature, a scale (lepís; squāma) is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran (butterfly and moth) species, scales are plates on the surface of the insect wing, and provide coloration. Scales are quite common and have evolved multiple times through convergent evolution, with varying structure and function. Scales are generally classified as part of an organism's integumentary system. There are various types of scales according to shape and to class of animal.
TuataraTuatara (Sphenodon punctatus) are reptiles endemic to New Zealand. Despite their close resemblance to lizards, they are part of a distinct lineage, the order Rhynchocephalia. The name tuatara is derived from the Māori language and means "peaks on the back". The single extant species of tuatara is the only surviving member of its order. Rhynchocephalians originated during the Triassic (~250 million years ago), reached worldwide distribution and peak diversity during the Jurassic and, with the exception of tuatara, were extinct by 60 million years ago.
