What are the characteristics of Lepidosaurs and what animals belong to this group?

Lepidosauria is a monophyletic group (i.e. a clade), containing all descendants of the last common ancestor of squamates and rhynchocephalians. Lepidosaurs can be distinguished from other reptiles via several traits, such as large keratinous scales which may overlap one another.

What are Hemipenes give their function?

A hemipenis (plural hemipenes) is one of a pair of intromittent organs of male squamates (snakes, lizards and worm lizards). Hemipenes are usually held inverted within the body, and are everted for reproduction via erectile tissue, much like that in the human penis.

Which groups make up clade Sauropsida?

The base of Sauropsida forks into two main groups of “reptiles”: Eureptilia (“true reptiles”) and Parareptilia (“next to reptiles”). Eureptilia encompasses all living reptiles (including birds), as well as various extinct groups.

How do you classify Squamata?

Classically, the Squamata order is divided into three suborders:

  1. Lacertilia, the lizards;
  2. Serpentes, the snakes;
  3. Amphisbaenia, the worm lizards.

What are the families of Squamata?


  • FamilyAcrochordidae. Acrochordidae: pictures (3)
  • FamilyAgamidae. Agamidae: information (1)
  • FamilyAmphisbaenia.
  • FamilyAmphisbaenidae. Amphisbaenidae: pictures (12)
  • FamilyAnguidae. Anguidae: information (1)
  • FamilyAniliidae. Aniliidae: pictures (4)
  • FamilyAnniellidae. Anniellidae: information (1)
  • FamilyAnomalepidae.

Do Lepidosaurs have scales?

The Lepidosaurians are reptiles with overlapping scales. They include two sub-classes, the Rhynocephalia and Squamata. Rhynocephalia is the oldest group, and has only one living species, the tutara (Sphenodon punctatus), that lives in New-Zealand.

What are some characteristics of crocodilians?

Large, solidly built, lizard-like reptiles, crocodilians have long flattened snouts, laterally compressed tails, and eyes, ears, and nostrils at the top of the head. They swim well and can move on land in a “high walk” and a “low walk”, while smaller species are even capable of galloping.

What is a prolapsed Hemipenis?

If you see a pink bulge or two under the cloaca of your male reptile it probably has a prolapsed hemipenis. If a hemipenis comes out and stays out, it may also dry out. If you are unable to get the hemipenis to retract at home, keep it moist with warm water or apply some vaseline or another lubricant.

Do snakes poop?

A good rule of thumb is that if a snake eats frequently, it will defecate frequently. If a snake eats infrequently, it will defecate infrequently. Simple in theory, this means that a snake may defecate only a few times a year. Because of this, up to 5-20% of a snake’s body weight at any given time may be fecal matter.

What is the difference between sauropsids and synapsids?

Synapsids include all mammals, including extinct mammalian species. Synapsids also include therapsids, which were mammal-like reptiles from which mammals evolved. Sauropsids include reptiles and birds, and can be further divided into anapsids and diapsids.

When did synapsids split from sauropsids?

about 312 million years ago
Synapsids and sauropsids split off from each other about 312 million years ago, during the late Carboniferous period.

Are there stem lepidosauromorphs in the fossil record?

As of 2018, most of the fossil taxa placed on the lepidosauromorph stem have been evicted to other (and varying) parts of the diapsid tree ( Simões et al., 2018) leaving only a handful of fragmentary potential stem lepidosauromorphs. Not really surprising given the fragmentary nature of these small animals’ remains.

What is Archosauromorpha in biology?

Archosauromorpha (Greek for “ruling lizard forms”) is a clade of diapsid reptiles containing all reptiles more closely related to archosaurs (such as crocodilians and dinosaurs, including birds) rather than lepidosaurs (such as tuataras, lizards, and snakes).

What is Sauropsida in biology?

Sauropsida (“lizard faces”) is a clade of amniotes, broadly equivalent to the class Reptilia. Sauropsida is the sister taxon to Synapsida, the clade of amniotes which includes mammals as its only modern representatives.

What is the difference between synapsids and sauropsids?

Although early synapsids have historically been referred to as “mammal-like reptiles,” all synapsids are more closely related to mammals than to any modern reptile. Sauropsids, on the other hand, include all amniotes more closely related to modern reptiles than to mammals.