ed kinds (see, for example, Doran et al. 2018; Frederico and McLain 2019; McLain et al. 2018; Wood 2005). It should also be noted that there are some species that do not fall within any of the colored clades (e.g., Prolacerta broomi and Euparkeria capensis). If we predict that these recognizable, non-archosaur archosauromorph units on Figure 1 represent distinct baramins, then we can hypothesize 6-10 created kinds (the higher number including the taxa falling outside of the colored clades). If, instead, we estimate the number of non-archosaur archosauromorph baramins as at the family level, then the number would be closer to ~12-15 created kinds. In this article, we will use statistical baraminological methods to test these hypotheses. However, before we address previous baraminology work on archosauromorphs, a brief survey of the various archosauromorph taxa is required. 1. “Protorosauria” Protorosauria is a likely polyphyletic grouping of archosauromorph reptiles known from Permian and Triassic rocks. The distinctive feature of “protorosaurs” is their long necks, which are made up of lengthened cervical vertebrae with ribs that extend backward to the vertebrae behind them. The name “Protorosauria” was given by English anatomist and palentologist Thomas Henry Huxley in 1871 for the animal Protorosaurus. In 1886, Francesco Bassani described a fossil of a reptile from the Middle Triassic Besano Formation along the border between Italy and Switzerland as a peculiar pterosaur, which he named Tribelesodon longobardicus. Later discoveries revealed that what were thought to be the elongated phalanges of a pterosaur were actually elongated neck vertebrae, which compared well with some from Germany that had been assigned to Tanystropheus conspicuus (Spiekman et al. 2021). Thus, Tribelesodon longobardicus was renamed Tanystropheus longobardicus. Tanystropheids are now a well-known group from Lower to Upper Triassic beds from Europe, Asia, North America (Pritchard et al. 2015), and South America (De Oliveira et al. 2018; De Oliveira et al. 2020). Dinocephalosaurus, a long-necked, fully aquatic “protorosaur” from the Middle Triassic rocks of southwest China (Li et al. 2004), is the stratigraphically lowest example of live birth in archosauromorphs (Liu et al. 2017). Among “protorosaurs”, Dinocephalosaurus has a neck that is noticeably longer due to an increase in the number of cervical vertebrae, unlike the condition in tanystropheids, where the neck is lengthened mainly by elongation of the cervical vertebrae (Li et al. 2004). Phylogenetic analyses place Dinocephalosaurus and Pectodens in Dinocephalosauridae, the sister taxon to Tanystropheidae (Spiekman et al. 2021). As if tanystropheids and dinocephalosaurids were not strange enough, the most bizarre flavor of “protorosaur” comes in the form of the sharovipterygids. Sharovipteryx mirabilis is known from a single fossil from Kyrgyzstan that shows evidence of a membrane stretched between its long legs. Unfortunately, the arms are not well preserved, so it is unclear if there was a membrane there, too. Dyke et al. (2006) modeled the gliding ability of Sharovipteryx and concluded it was a delta-wing glider, but that it would have needed some kind of small anterior canard wing, attached to the forelimbs or the neck for stability. In 2016, Dzik and Sulej announced the discovery of a close relative to Sharovipteryx from Poland, which they named Ozimek volans. They suspect it was also a glider, although no evidence of a membrane was discovered on the fossil. Surprisingly, recent phylogenetic work has recovered Ozimek (and thus Sharovipterygidae) within Tanystropheidae (e.g., Spiekman et al. 2021). We hypothesize that Tanystropheidae is either a holobaramin or monobaramin within a larger holobaramin that also contains Dinocephalosauridae. However, we are unsure of how other “protorosaurs” might be related to this group. 2. Allokotosauria The name Allokotosauria was derived from Greek meaning “strange reptiles,” which suits them well. Allokotosaurs are a group of archosauromorph reptiles known from Middle to Upper Triassic rocks. Allokotosauria consists of two families: Azendohsauridae and Trilophosauridae. Trilophosauridae was named for Trilophosaurus buettneri by E.C Case in 1928. Trilophosaurus was named for its peculiar tricuspid teeth that are unknown in other archosauromorphs. It is an herbivore, possessing a keratinous beak in addition to its teeth, and it also has a long tail and grasping claws, allowing it to live an arboreal lifestyle probably reminiscent of an iguana (Spielmann et al. 2008). A very peculiar animal with a long snout named Teraterpeton, which was originally placed in its own family called Teraterpetidae (Sues 2003), has been included in Trilophosauridae because it is similar in having chisel-like cheek teeth and a toothless beak (Pritchard and Sues 2019). Azendohsauridae was more recently named than Trilophosauridae (Nesbitt et al. 2015), and it includes animals like Azendohsaurus and Shringasaurus, a peculiar reptile with Triceratops-like brow horns (Sengupta et al. 2017). Azendohsaurids often have very short and robust limbs, with digits that are short and stout, possessing noticeably broad, curved claws on all four feet (Nesbitt et al. 2015). They also possess a single midline narial opening on the skull (Nesbitt et al. 2022). Many azendohsaurids were herbivorous, although there are some carnivorous forms known (e.g., Malerisaurus and Puercosuchus) (Marsh et al. 2022). Azendohsauridae and Trilophosauridae have been recovered as sister taxa within Allokotosauria in recent phylogenies (e.g., Ezcurra et al. 2016; Nesbitt et al. 2022). Synapomorphies for Allokotosauria include a distinct morphology of the distal condyles of the humerus, a prominent tubercle distal to the glenoid fossa of the scapula, and a rugose surface of the frontal near the orbit margin (Nesbitt et al. 2015). Due to their peculiarities when compared to other archosauromorphs and similarities that allokotosaurs share, we hypothesize that Allokotosauria (Azendohsauridae + Trilophosauridae) is either a holobaramin composed of two monobaramins or two separate holobaramins. 3. Rhynchosauria Rhynchosaurs all possess two long, curved teeth that grow from the premaxilla right at the front of the face. The beak-like structure to these paired teeth makes them perfect for holding and tearing into soft foods (Mukherjee and Ray 2022). This unique feature inspired Richard Owen in 1842a to give the first discovered form the name Rhynchosaurus, meaning “beaked lizard.” Because of their unique teeth and wide heads that seem too broad for the rest of their body, rhynchosaurs are easy to distinguish from other archosauromorphs. Rhynchosaur fossils have been found in South Africa, South America, Europe, India, Tanzania, Madagascar, and North America. The genus Hyperodapedon is one of the most commonly found tetrapods in Triassic beds that contain dinosaurs, making this genus a biostratigraphic index fossil (Ezcurra et al. 2016). The species that are considered “basal” rhynchosaurs generally have smaller heads (~90 mm) than most of the others (~140 mm, with the exception of Isalorhynchus genovefae). This leads Ezcurra et al. (2016) to conclude that there were two distinct increases in skull MCLAIN, CLAUSEN, PEREZ, BEEBE, AND AHTEN Archosauromorph Baraminology 2023 ICC 489
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