six.dos.1 Diagnosing the Genus Revueltosaurus
The newest holotypes out-of R. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), while the has just attributed varieties “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert ainsi que al., 2012 ) for every single happened to be just one isolated enamel which was the basis getting its particular prognosis. Most recently, Heckert ainsi que al. ( 2012 ) identified the fresh new genus Revueltosaurus (spanning Roentgen. callenderi, Roentgen. hunti, and you will Roentgen. olseni) utilizing the pursuing the combination of reputation states: size (enamel crowns around seven so you can 15-mm tall); multiple brief denticles (more than eight for each carina) that will be offset (sub-perpendicular) on tooth margin; denticles proportionately brief and often used to blued ne demek the tooth of the right occlusion; shortage of a true cingulum; premaxillary enamel crowns which can be as much as doubly high because the maxillary/dentary tooth crowns and you may weakly recurved; and you may maxillary/dentary tooth crowns phyllodont (leaf-shaped). g., Ezcurra, 2016 ). Eg, the blend of your size of the teeth, exactly how many new denticles, additionally the direction of your denticles convergence with other distantly associated taxa (e.g., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn ainsi que al., 2010 ). The character “denticles proportionately short and frequently worn to the enamel of the precise occlusion” does not have precision in terms of what’s thought “quick,” and don trend is tough to rule out various other taxa and you can hinges on a certain age of tooth when you look at the substitute for period (i.age., young teeth would not be diagnosable as there would not be worn). Additionally, its lack of apomorphic reputation says (e.grams., absence of cingulum) really should not be included in an analysis, since they’re symplesiomorphies. Additionally, the latest task out of enamel updates based on one enamel (e.grams., premaxillary tooth crowns is everything two times as significant because maxillary/dentary enamel crowns and you may weakly recurved; maxillary/dentary tooth crowns leaf molded) cannot be calculated throughout the original types of topic, and even with additional teeth in the same area, simply craniodental topic with white teeth also have the new connection off enamel shape and you can enamel updates. Hence, the fresh advised tooth status of your holotype pearly whites out of K. hunti and P. olseni is thought considering an enthusiastic inferred intimate connection with Roentgen. callenderi, which is identified from craniodental matter which have white teeth (come across above). To conclude, new genus Revueltosaurus sensu lato can’t be effectively and sustainably recognized in line with the sorts of content from R. callenderi, K. hunti, and you may P. olseni and we also for this reason restrict this new genus to 1 varieties, Roentgen. callenderi. Therefore, i propose that “R”. hunti retain the subjective junior word Krzyzanowskisaurus hunti given that erected of the Heckert ( 2005 ) and you can “R”. olseni retain the subjective senior synonym Pekinosaurus olseni. We after that caution the latest assignment of any existing separated tooth taxa to help you Revueltosaurus.
We create understand that in the future, with more done topic, Roentgen. callenderi, Krzyzanowskisaurus hunti, and Pekinosaurus olseni will get portray a monophyletic genus Revueltosaurus, but an assignment of the many three kinds to 1 genus is not already you can easily whilst can make an one priori expectation in the dating (look for less than) which is parallel on the unique argument the Revueltosaurus white teeth were assignable to Ornithischia first off. This could has actually undesirable flowing outcomes on the next macroevolutionary education (elizabeth.grams., biogeography and you can paleocology). Rather, it can be quite possible these particular taxa may begin aside as distantly related.
six.2.dos What is Krzyzanowskisaurus hunti?
Heckert ( 2002 ) demonstrated “Revueltosaurus” hunti, later assigned to the genus Krzyzanowskisaurus (Heckert, 2005 ), according to remote white teeth from the Los Esteros Person in the latest Santa Rosa Development (Dockum Class) for the central This new Mexico plus the Bluish Mesa Person in the new Chinle Creation in the east Washington (kind of area away from A good. geoffreyi-look for ), and contains already been approved throughout the lower Chinle Development during the southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti pearly whites are well-known out-of R. callenderi teeth because of the exposure out of a ridge (“cingulum”) on the bottom of the tooth crown, hence links to the carinae which will be usually denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, et al., 2007 ; Rates 14a, b). To start with, Krzyzanowskisaurus is titled considering the different morphology of your own pearly whites between the two forms in addition to dispute your Krzyzanowskisaurus white teeth nonetheless had been assignable in order to an ornithischian in lieu of an effective pseudosuchian (Heckert, 2005 ). Irmis, Parker, ainsi que al. ( 2007 ) disagreed for the task off Krzyzanowskisaurus hunti towards the Ornithischia oriented into similar objections outlining the issues out of delegating remote white teeth in order to ornithischians since the displayed before as well as the construction you to Heckert ( 2002 , 2005 ) identified as an effective “cingulum” wasn’t homologous with similar formations in ornithischian dinosaurs. Additionally, Irmis, Parker, mais aussi al. ( 2007 ) in addition to noted one a Revueltosaurus-such as for instance squamosal, quadrate, and you may osteoderms have been together with discovered at a similar Washington area because Krzyzanowskisaurus hunti white teeth, just as got taken place at the method of area getting Roentgen. callenderi (Check mais aussi al., 2005 ).