6.dos.step 1 Diagnosis the new Genus Revueltosaurus
The new holotypes regarding R. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), and recently charged kinds “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert mais aussi al., 2012 ) for each and every are just one remote tooth which had been the foundation to own the particular diagnosis. Most recently, Heckert et al. ( 2012 ) identified the genus Revueltosaurus (spanning Roentgen. callenderi, R. hunti, and you may R. olseni) with the adopting the mixture of profile claims: size (tooth crowns around eight so you can fifteen-mm significant); numerous quick denticles (more than eight for every single carina) that will be offset (sub-perpendicular) toward tooth margin; denticles proportionately quick and sometimes used for the enamel of the particular occlusion; decreased a real cingulum; premaxillary enamel crowns which can be whenever two times as significant since maxillary/dentary tooth crowns and you can weakly recurved; and you can maxillary/dentary tooth crowns phyllodont (leaf-shaped). g., Ezcurra, 2016 ). Such, the blend of measurements of tooth, what number of this new denticles, and the orientation of one’s denticles convergence together with other distantly relevant taxa (e.grams., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn mais aussi al., 2010 ). The type “denticles proportionately quick and frequently worn towards the tooth because of the accurate occlusion” lacks precision when it comes to what’s considered “small,” therefore the wear trend is difficult so you’re able to eliminate in other taxa and depends on a particular age of tooth from inside the substitute for course (we.e., younger teeth wouldn’t be diagnosable as there would not be worn). In addition, the absence of apomorphic character claims (elizabeth.grams., lack of cingulum) shouldn’t be used in an analysis, because they are symplesiomorphies. As well, the latest project out-of tooth position based on a single enamel (elizabeth.grams., premaxillary enamel crowns try just as much as twice as significant because maxillary/dentary tooth crowns and weakly recurved; maxillary/dentary tooth crowns leaf designed) can not be calculated about brand new kind of topic, plus with white teeth throughout the same area, merely craniodental situation with teeth can provide this new association regarding enamel profile and tooth updates. Ergo, the newest advised tooth status of your holotype pearly whites from K. hunti and you will P. olseni is assumed according to a keen inferred romantic reference to Roentgen. callenderi, that’s known of craniodental situation which have white teeth (discover significantly more than). To summarize, the fresh new genus Revueltosaurus sensu lato can not be effectively and sustainably recognized according to research by the form of information off R. callenderi, K. hunti, and you can P. olseni therefore therefore restriction the newest genus to a single species, R. callenderi. Therefore, we propose that “R”. hunti retain the subjective junior synonym Krzyzanowskisaurus hunti because the erected by Heckert ( 2005 ) and you may “R”. olseni retain the subjective elderly word Pekinosaurus olseni. We subsequent warning new task of any present separated tooth taxa to help you Revueltosaurus.
We create recognize that subsequently, with more over situation, R. callenderi, Krzyzanowskisaurus hunti, and Pekinosaurus olseni will get show a great monophyletic genus Revueltosaurus, however, a project of all around three varieties to a single genus is not already you’ll be able to whilst produces a the priori presumption regarding dating (look for less than) that’s synchronous on totally new conflict that Revueltosaurus white teeth was assignable so you can Ornithischia to begin with. This might has undesired streaming outcomes into then macroevolutionary education (elizabeth.g., biogeography and you can paleocology). Instead, it is also possible that these taxa may start aside are distantly related.
six.dos.2 What exactly is Krzyzanowskisaurus hunti?
Heckert ( 2002 ) revealed “Revueltosaurus” hunti, afterwards assigned to the new genus Krzyzanowskisaurus (Heckert, 2005 ), considering remote white teeth on the Los Esteros Member of the brand new Santa Rosa Development (Dockum Group) inside the main The fresh new Mexico together with Bluish Mesa Person in the fresh new Chinle Creation in east Washington (kind of locality off A good. geoffreyi-get a hold of ), and also been recently recognized on lower Chinle Development when you look at the southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti teeth is recognized out of R. callenderi pearly whites because of the visibility out of a great ridge (“cingulum”) toward the base of your own tooth crown, hence connects towards the carinae that will be will denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, et al., 2007 ; Numbers 14a, b). To begin with, Krzyzanowskisaurus try named considering the different morphology of your own pearly whites ranging from the 2 models plus the disagreement your Krzyzanowskisaurus white teeth nevertheless were assignable in order to a keen ornithischian in place of an excellent pseudosuchian (Heckert, 2005 ). Irmis, Parker, et al. ( 2007 ) disagreed to the project away from Krzyzanowskisaurus hunti on Ornithischia cybermen web situated for the equivalent arguments outlining the difficulties of delegating remote white teeth in order to ornithischians given that shown in past times as well as the build one to Heckert ( 2002 , 2005 ) identified as a great “cingulum” wasn’t homologous with the exact same structures when you look at the ornithischian dinosaurs. Also, Irmis, Parker, et al. ( 2007 ) and noted you to an effective Revueltosaurus-eg squamosal, quadrate, and you will osteoderms was basically plus discovered at a similar Arizona locality given that Krzyzanowskisaurus hunti pearly whites, exactly as got took place at the kind of locality to possess Roentgen. callenderi (Check mais aussi al., 2005 ).