Panarthropoda is a proposed animal clade containing the extant phyla Arthropoda, Tardigrada and Onychophora. Panarthropods also include extinct marine legged worms known as lobopodians ("Lobopodia"), a paraphyletic group where the last common ancestor and basal members (stem-group) of each extant panarthropod phylum are thought to have risen. However the term "Lobopodia" is sometimes expanded to include tardigrades and onychophorans as well.
Gnetophyta is a division of plants, grouped within the gymnosperms, that consists of some 70 species across the three relict genera: Gnetum, Welwitschia, and Ephedra. The earliest unambiguous records of the group date to the Jurassic, and they achieved their highest diversity during the Early Cretaceous. The primary difference between gnetophytes and other gymnosperms is the presence of vessel elements, a system of small tubes (xylem) that transport water within the plant, similar to those found in flowering plants. Because of this, gnetophytes were once thought to be the closest gymnosperm relatives to flowering plants, but more recent molecular studies have brought this hypothesis into question, with many recent phylogenies finding them to be nested within the conifers.
Squamata is the largest order of reptiles, comprising lizards and snakes. With over 12,162 species, it is also the second-largest order of extant (living) vertebrates, after the perciform fish. Squamates are distinguished by their skins, which bear horny scales or shields, and must periodically engage in molting. They also possess movable quadrate bones, making possible movement of the upper jaw relative to the neurocranium. This is particularly visible in snakes, which are able to open their mouths very wide to accommodate comparatively large prey. Squamates are the most variably sized living reptiles, ranging from the 16 mm (0.63 in) dwarf gecko to the 6.5 m (21 ft) reticulated python. The now-extinct mosasaurs reached lengths over 14 m (46 ft).
The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives, including the widespread green iguana.
Paenungulata is a clade of "sub-ungulates", which groups three extant mammal orders: Proboscidea, Sirenia, and Hyracoidea (hyraxes). At least two more possible orders are known only as fossils, namely Embrithopoda and Desmostylia.
The Caudata are a group of amphibians containing the extant salamanders and all extinct species of amphibians more closely related to salamanders than to frogs. They are typically characterized by a superficially lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults.
Caecilians are a group of limbless, vermiform (worm-shaped) or serpentine (snake-shaped) amphibians with small or sometimes nonexistent eyes. They mostly live hidden in soil or in streambeds, and this cryptic lifestyle renders caecilians among the least familiar amphibians. Modern caecilians live in the tropics of South and Central America, Africa, and southern Asia. Caecilians feed on small subterranean creatures such as earthworms. The body is cylindrical and often darkly coloured, and the skull is bullet-shaped and strongly built. Caecilian heads have several unique adaptations, including fused cranial and jaw bones, a two-part system of jaw muscles, and a chemosensory tentacle in front of the eye. The skin is slimy and bears ringlike markings or grooves and may contain scales.
Aulopiformes is a diverse order of marine ray-finned fish consisting of some 15 extant and several prehistoric families with about 45 genera and over 230 species. The common names grinners, lizardfishes and allies, or aulopiforms are sometimes used for this group. The scientific name means "Aulopus-shaped", from Aulopus + the standard fish order suffix "-formes". It ultimately derives from Ancient Greek aulós + Latin forma, the former in reference to the elongated shape of many aulopiforms.
The Pipidae are a family of primitive, tongueless frogs. There are 41 species in the family, found in tropical South America and sub-Saharan Africa.
Cophylinae is a subfamily of microhylid frogs endemic to Madagascar. It has over 100 species in eight genera. Members of this subfamily range from minute to fairly large, and they are highly ecologically diverse. DNA barcode research has revealed a significant taxonomic gap in this subfamily, and an estimated 70+ candidate species were identified. Many of these have subsequently been described, as well as numerous new discoveries.
Merlin's dwarf gray frog, or Merlin's clawed frog, is a species of frog in the family Pipidae. It is monotypic within the genus Pseudhymenochirus. It is found in southern Guinea-Bissau, western Guinea, and southern Sierra Leone.
The Alethinophidia are an infraorder of snakes that includes all snakes other than blind snakes and thread snakes. Snakes have long been grouped into families within Alethinophidia based on their morphology, especially that of their teeth. More modern phylogenetic hypotheses using genetic data support the recognition of 19 extant families, although the taxonomy of alethinophidian snakes has long been debated, and ultimately the decision whether to assign a particular clade to a particular Linnaean rank is arbitrary.
Hyloidea is a superfamily of frogs. Hyloidea accounts for 54% of all living anuran species. The superfamily Hyloidea branched off from its closest relative, the Australobatrachia, during the mid-Cretaceous. The fossil evidence found during the Cretaceous-Paleogene extinction event could not determine the effects upon the frogs, due to the lack of fossils. Increased forestation erupted after this extinction, possibly leading to more arboreal adaptations of these anurans to be best suited for this habitat.
Avitabatrachus uliana is the only species discovered so far in the extinct genus Avitabatrachus, a genus of prehistoric frogs that lived in the Middle Cretaceous. Fossils of A. uliana were found in the Candeleros Formation of northwestern Patagonia in Argentina. This prehistoric amphibian was properly described in 2000 and was then concluded to be most closely related to Pipidae frogs. Hence, it was included in Pipimorpha. A subsequent phylogenetic analysis confirmed this conclusion, and further suggested that Avitabatrachus uliana is more closely related to Pipidae and Shelaniinae than to Palaeobatrachus.
Vulcanobatrachus is an extinct genus of fossil frog. The genus contains the single species Vulcanobatrachus mandelai found at Marydale, South Africa, described in 2005 and named after Nelson Mandela. The genus owes its name to the fact that fossils were recovered from an extinct volcanic crater lake of Late Cretaceous age. The fossil frogs are assumed to have died following a limnic eruption (a degassing event possibly of CO2) by the volcano.
Shelania is an extinct genus of prehistoric frogs that lived in South America during the Eocene. Its type species is Shelania pascuali. Fossils of Shelania have been found in the Mustersan Vaca Mahuida and Laguna del Hunco Formations of Argentina. Shelania is the type taxon of the Shelaniinae, which was erected for an unranked clade that also includes the early anurans Saltenia, Kuruleufenia, and Patagopipa. A more recent phylogenetic analysis further suggested that Shelania is more closely related to Pipidae than to Palaeobatrachus, and that the second species previously attributed to Shelania is not sufficiently closely related to the type-species to be retained in Shelania.
Singidella is an extinct genus of prehistoric frog from the Eocene of Tanzania. There is currently only one described species, S. latecostata. Its generic name is derived from Singida, the city near which the only known specimens were found, and the specific name translates as "wide ribs" from Latin. It is a member of the family Pipidae and is closely related to the extant African dwarf frogs (Hymenochirus) and Merlin's dwarf gray frog (Pseudohymenochirus) and the Cretaceous frog Pachycentrata of Niger. Adult individuals were estimated at 41-45 mm in length from snout to vent.
Thoraciliacus rostriceps is an extinct species of frog from the Cretaceous period and the only species of the genus Thoraciliacus, which is classified in the unranked clade Pipimorpha. Fossils of T. rostriceps were found in Makhtesh Ramon, Negev Desert, Israel and it is believed they lived during the Barremian. Other fossils have been found near Marydale, South Africa in an Upper Cretaceous lake.
Pipoidea are a clade of frogs, that contains the most recent common ancestor of living Pipidae and Rhinophrynidae as well as all its descendants. It is broadly equivalent to Xenoanura.
Sooglossoidea is a superfamily of frogs. It contains only two highly divergent families consisting of three genera with two species each, one family being found in southwestern India and the other in the Seychelles.
