Varanopidae is an extinct family of amniotes known from the Late Carboniferous to Middle Permian that resembled monitor lizards (with the name of the group deriving from the monitor lizard genus Varanus) and may have filled a similar niche. Typically, they are considered to be relatively basal synapsids (and thus more closely related to mammals than to reptiles), although some studies from the late 2010s recovered them being taxonomically closer to diapsid reptiles, recent studies from the early 2020s support their traditional placement as synapsids on the basis of high degree of bone labyrinth ossification, maxillary canal morphology and phylogenetic analyses. A varanopid from the late Middle Permian Pristerognathus Assemblage Zone (Capitanian) is the youngest known varanopid and the last member of the "pelycosaur" group of synapsids. Thus, Varanopidae vanishes from the fossil record at the same time as dinocephalians, plausibly as a result of a major mass extinction event that has been called the "Dinocephalian extinction event".
- ⭐ Core Definition: Varanopidae
- Varanopidae in the context of Incertae sedis
- Varanopidae in the context of Sauropsid
Varanopidae in the context of Incertae sedis
Incertae sedis (Latin for 'of uncertain placement') or problematica is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty at specific taxonomic levels is indicated by incertae familiae (of uncertain family), incerti subordinis (of uncertain suborder), incerti ordinis (of uncertain order) and similar terms.
View the full Wikipedia page for Incertae sedisVaranopidae in the context of Sauropsid
Sauropsida (Greek for "lizard faces") is a clade of amniotes, broadly equivalent to the class Reptilia, though typically used in a broader sense to also include extinct stem-group relatives of modern reptiles and birds (which, as theropod dinosaurs, are nested within reptiles as more closely related to crocodilians than to lizards or turtles). The most popular definition states that Sauropsida is the sibling taxon to Synapsida, the other clade of amniotes which includes mammals as its only modern representatives. 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. This includes Aves (birds), which are a group of theropod dinosaurs despite originally being named as a separate class in Linnaean taxonomy.
The base of Sauropsida is traditionally divided into 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. Parareptilia is typically considered to be an entirely extinct group, though a few hypotheses for the origin of turtles have suggested that they belong to the parareptiles. The clades Recumbirostra and Varanopidae, traditionally thought to be lepospondyls and synapsids respectively, may also be basal sauropsids. The term "Sauropsida" originated in 1864 with Thomas Henry Huxley, who grouped birds with reptiles based on fossil evidence. The divisions of "Eureptilia" and "Parareptilia" have been challenged in a number of recent studies, who find that they do not represent monophyletic groups.
View the full Wikipedia page for Sauropsid