Protorothyrididae is an extinct

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

of small, lizard-like reptiles belonging to Eureptilia. Their skulls did not have fenestrae, like the more derived diapsids. Protorothyridids lived from the Late Carboniferous to

Early Permian 01 or '01 may refer to: * The year 2001, or any year ending with 01 * The month of January * 1 (number) Music * 01'' (Richard Müller album), 2001 * ''01'' (Son of Dave album), 2000 * ''01'' (Urban Zakapa album), 2011 * ''O1'' (Hiroyuki Sawano ...

periods, in what is now North America. Many genera of primitive reptiles were thought to be protorothyridids. ''

Brouffia ''Brouffia'' is an extinct genus of Late Carboniferous (late Westphalian stage) basal reptile known from Pilsen of Czech Republic. It is known from a single partial skeleton, the holotype ČGH III B.21.C.587 and MP 451 (part and ...

'', '' Coelostegus'', '' Paleothyris'' and '' Hylonomus'', for example, were found to be more

basal Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''. Science * Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure * Basal (medicine), a minimal level that is nec ...

eureptiles in Muller and Reisz (2006), making the family as historically defined

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

, though three genera, '' Protorothyris, Anthracodromeus,'' and '' Cephalerpeton'', were recovered as a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic ...

group. ''Anthracodromeus'', ''Paleothyris'', and ''Protorothyris w''e recovered as a monophyletic group in Ford and Benson (2020) (who did not sample ''Cephalerpeton''), who recovered them as more derived than captorhinids and ''Hylonomus'', but less so than araeoscelidians. ''Anthracodromeus'' is the earliest known reptile to display adaptations to

climbing Climbing is the activity of using one's hands, feet, or any other part of the body to ascend a steep topographical object that can range from the world's tallest mountains (e.g. the eight thousanders), to small boulders. Climbing is done ...

. The majority of phylogenetic studies recover protorothyridids as

members of Eureptilia; however, Simões ''et al.'' (2022) recover them as

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushr ...

- amniotes instead.

References

Prehistoric reptile families Prehistoric romeriids Taxa named by Llewellyn Ivor Price {{paleo-reptile-stub