cladistics is the kind of analysis that focuses on the evolution of derived characteristics.
cladistics is the kind of analysis that focuses on the evolution of derived characteristics.
the kind of analysis that focuses on the evolution of derived characteristics?
cladistics
"arizonasaurus" was closely related to "ctenosauriscus"; and, together with a few other genera, they make up ctenosauriscidae. the ctenosauriscids were closely related to the poposaurids, as shown by a few shared derived characteristics. the pelvic girdle in "arizonasaurus" unites this taxon with "ctenosauriscus", "lotosaurus", "bromsgroveia", and "hypselorhachus". together, newly identified pseudosuchian features act as evidence that poposaurids, such as "poposaurus", "sillosuchus", and "chatterjeea", and ctenosauriscids form a monophyletic group that is derived rauisuchians.









































below is a phylogenetic cladogram simplified from butler "et al." in 2011 showing the cladistics of archosauriformes, focusing mostly on pseudosuchia:









































section::::biogeography.
arizonasaurus
classification of hupehsuchia remains difficult because most of the derived characters exhibited in the clade that can be helpful in phylogenetic analyses are also present in other unrelated groups of secondarily aquatic reptiles, and the overall record of diapsids during the late permian-early triassic is relatively poor, making it difficult to find any closely related or ancestral taxa. even higher level classification is difficult because many of the plesiomorphies that characterize such groups are absent in the highly derived, marine adapted hupehsuchians. for example, several characteristics suggest that hupehsuchia belongs within neodiapsida, but most of the derived characteristics that define the clade are absent or hard to distinguish in hupehsuchians, even though their ancestors may have possessed these characteristics at one point. three derived characteristics of neodiapsida are a reduced number of teeth on the pterygoid, an absence of teeth on the parasphenoid, and a lack of caniniform maxillary teeth, but none of these apply to hupehsuchians because they lack teeth altogether. many derived characteristics that define neodiapsids regard the limbs and girdles, but these characteristics are not seen in marine reptiles because the limbs and girdles are too highly modified. many characteristics of the skull cannot be seen in hupehsuchians due to poor preservation of remains. therefore, any placement of hupehsuchia within neodiapsida remains tentative until more specimens are found.
hupehsuchia