DiapsidDiapsids ("two arches") are a clade of sauropsids, distinguished from other reptiles by the presence (at least ancestrally) of two holes, known as temporal fenestrae, in each side of their skulls. The earliest traditionally identified diapsids, the araeoscelidians, appeared about three hundred million years ago during the late Carboniferous period.
TurtleOrder of reptiles with a shellTurtles (orderTestudines) are reptiles characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins.
Temporal fenestraTemporal fenestrae are openings in the temporal region of the skull of some amniotes, behind the orbit (eye socket). These openings have historically been used to track the evolution and affinities of reptiles. Temporal fenestrae are commonly (although not universally) seen in the fossilized skulls of dinosaurs and other sauropsids (the total group of reptiles, including birds).
TortoiseTortoises ( TOR-təs-iz) are reptiles of the family Testudinidae of the order Testudines (Latin for "tortoise"). Like other testudines, tortoises have a shell to protect from predation and other threats. The shell in tortoises is generally hard, and like other members of the suborder Cryptodira, they retract their necks and heads directly backward into the shell to protect them.
SynapsidaSynapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant reptiles and birds). Synapsids have a single lower temporal fenestra, an opening low in the skull roof behind each eye socket.
PermianSixth and last period of the Paleozoic EraSubdivision of the Permian according to the ICS, as of 2023.Vertical axis scale: Millions of years agoEtymologyName formalityFormalUsage informationRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitPeriodStratigraphic unitSystemTime span formalityFormalLower boundary definitionFAD of the ConodontStreptognathodus isolatus within the morphotypeStreptognathodus wabaunsensis chronocline.Lower boundary GSSPAidaralash, Ural Mountains, Kazakhstan50°14′45″N57°53′29″E / 50.2458°N 57.8914°E / 50.2458; 57.8914Lower GSSP ratified1996Upper boundary definitionFAD of the Conodont Hindeodus parvus.Upper boundary GSSPMeishan, Zhejiang, China31°04′47″N119°42′21″E / 31.0798°N 119.7058°E / 31.0798; 119.7058Upper GSSP ratified2001The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years, from the end of the Carboniferous Period 298.9 Ma (million years ago) to the beginning of the Triassic Period 251.902 Ma.
CarboniferousFifth period of the Paleozoic EraSubdivision of the Carboniferous according to the ICS, as of 2024.Vertical axis scale: Millions of years agoEtymologyName formalityFormalNickname(s)Age of Amphibians or ReptilesUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitPeriodStratigraphic unitSystemFirst proposed byWilliam Daniel Conybeare and William Phillips, 1822Time span formalityFormalLower boundary definitionFAD of the ConodontSiphonodella sulcata (discovered to have biostratigraphic issues as of 2006)Lower boundary GSSPLa Serre, Montagne Noire, France43°33′20″N3°21′26″E / 43.5555°N 3.3573°E / 43.5555; 3.3573Lower GSSP ratified1990Upper boundary definitionFAD of the ConodontStreptognathodus isolatus within the morphotypeStreptognathodus wabaunsensis chronoclineUpper boundary GSSPAidaralash, Ural Mountains, Kazakhstan50°14′45″N57°53′29″E / 50.2458°N 57.8914°E / 50.2458; 57.8914Upper GSSP ratified1996Atmospheric and climatic dataSea level above present dayFalling from 120 m to present-day level throughout the Mississippian, then rising steadily to about 80 m at end of periodThe Carboniferous ( ) is a geologic period and system of the Paleozoicera that spans 60 million years, from the end of the Devonian Period 358.86 Ma (million years ago) to the beginning of the Permian Period, 298.9 Ma.
AmnioteAmniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Amniotes evolved from amphibious stem tetrapod ancestors during the Carboniferous period. Amniota is defined as the smallest crown clade (the group including all descendants of the last common ancestor) containing humans, the Greek tortoise, and the Nile crocodile.
ParaphylyParaphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic with respect to the excluded subgroups. In contrast, a monophyletic grouping (a clade) includes a common ancestor and all of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics.
Temple (anatomy)The temple, also known as the pterion, is a latch where four skull bones intersect: the frontal, parietal, temporal, and sphenoid. It is located on the side of the head behind the eye between the forehead and the ear. The temporal muscle covers this area and is used during mastication.
MonophylyIn biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: the grouping contains its own most recent common ancestor (or more precisely an ancestral population), i.e. excludes non-descendants of that common ancestorthe grouping contains all the descendants of that common ancestor, without exceptionMonophyly is contrasted with paraphyly and polyphyly as shown in the second diagram.*As an Amazon Associate I earn from qualifying purchases.