6.dos.1 Diagnosis the fresh new Genus Revueltosaurus
The fresh holotypes out of R. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), and also the has just attributed varieties “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert et al., 2012 ) for every single comprise a single separated enamel which had been the cornerstone to possess its particular diagnosis. Of late, Heckert et al. ( 2012 ) identified the fresh genus Revueltosaurus (comprising Roentgen. callenderi, R. hunti, and you will Roentgen. olseni) with the adopting the mix of reputation claims: proportions (tooth crowns around seven in order to 15-mm extreme); multiple short denticles (over 7 each carina) that are offset (sub-perpendicular) towards the enamel margin; denticles proportionately quick and frequently used on enamel because of the right occlusion; diminished a real cingulum; premaxillary tooth crowns that are up to two times as extreme just like the maxillary/dentary enamel crowns and weakly recurved; and maxillary/dentary enamel crowns phyllodont (leaf-shaped). grams., Ezcurra, 2016 ). Instance, the combination of your own sized the teeth, what amount of brand new denticles, plus the positioning of denticles overlap together with other distantly associated taxa (age.grams., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn ainsi que al., 2010 ). The smoothness “denticles proportionately brief and frequently worn with the tooth from the direct occlusion” does not have reliability regarding what is experienced “small,” and the don trend is difficult to eliminate in other taxa and you will utilizes a specific chronilogical age of enamel when you look at the replacement period (i.age., young pearly whites wouldn’t be diagnosable as there would not be worn). Furthermore, its lack of apomorphic profile says (elizabeth.grams., absence of cingulum) shouldn’t be included in an analysis, because they are symplesiomorphies. At exactly the same time, new project regarding tooth reputation according to an individual tooth (age.g., premaxillary tooth crowns is just as much as doubly high due to the fact maxillary/dentary tooth crowns and you will weakly recurved; maxillary/dentary tooth crowns leaf shaped) cannot be computed throughout the totally new sort of topic, plus with additional teeth on the exact same area, merely craniodental procedure that have pearly whites offer this new relationship regarding tooth shape and you will tooth condition. Ergo, the latest proposed enamel updates of one’s holotype teeth out of K. hunti and P. olseni is thought predicated on a keen inferred intimate experience of R. callenderi, that is understood out of craniodental point which have pearly whites (pick a lot more than). In conclusion, new genus Revueltosaurus sensu lato can’t be sufficiently and you will sustainably recognized in accordance with the types of materials of R. callenderi, K. hunti, and you will P. olseni therefore we hence limitation the new genus to a single varieties, Roentgen. callenderi. As a result, we propose that “R”. hunti maintain the subjective junior synonym Krzyzanowskisaurus hunti due to the fact erected from the Heckert ( 2005 ) and you may “R”. olseni maintain the personal elderly synonym Pekinosaurus olseni. I next warning new project of every present separated tooth taxa to help you Revueltosaurus.
I create keep in mind that later on, with additional done question, R. callenderi, Krzyzanowskisaurus hunti, and you can Pekinosaurus olseni can get depict a beneficial monophyletic genus Revueltosaurus, but a task of all three types to a single genus isn’t already you’ll whilst produces an a priori assumption regarding matchmaking (see lower than) which is synchronous to your completely new dispute that Revueltosaurus teeth was assignable so you’re able to Ornithischia first off. This might has unwelcome streaming outcomes with the then macroevolutionary training (elizabeth.g., biogeography and paleocology). Rather, it is reasonably quite possible these particular taxa may turn out to-be distantly relevant.
6.dos.dos What’s Krzyzanowskisaurus hunti?
Heckert ( 2002 ) revealed “Revueltosaurus” hunti, later on assigned to the newest genus Krzyzanowskisaurus (Heckert, 2005 ), considering separated teeth throughout the Los Esteros Member of the fresh new Santa Rosa Formation (Dockum Category) in the main The fresh new Mexico additionally the Bluish Mesa Person in the fresh Chinle Development inside the east Washington (form of locality of A great. geoffreyi-find ), and also been already acknowledged regarding all the way down Chinle Formation inside southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti pearly whites try notable out-of Roentgen. callenderi white teeth because of the presence out of good ridge (“cingulum”) on the bottom of tooth crown, and that connects to your carinae which will be commonly denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, ainsi que al., 2007 ; Rates 14a, b). To start with, Krzyzanowskisaurus is titled given the disparate morphology of teeth ranging from both variations as well as the dispute the Krzyzanowskisaurus pearly whites however were assignable in order to an ornithischian in the place of a beneficial pseudosuchian (Heckert, 2005 ). Irmis, Parker, et al. ( 2007 ) disagreed on the task out-of Krzyzanowskisaurus hunti into Ornithischia mainly based to the equivalent arguments outlining the difficulties out of delegating isolated pearly whites to ornithischians because the showed in the past additionally the framework one to Heckert ( 2002 , 2005 ) recognized as a good “cingulum” was not homologous with the exact same formations from inside the ornithischian dinosaurs. In addition, Irmis, Parker, ainsi que al. ( 2007 ) plus listed that an effective Revueltosaurus-for example squamosal, quadrate, and osteoderms have been in addition to available at a comparable Arizona locality since the Krzyzanowskisaurus hunti pearly whites, just as had taken place in the kind of area to have Roentgen. callenderi (Check et al., 2005 ).