6.dos.1 Diagnosis the Genus Revueltosaurus
The brand new holotypes regarding R. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), in addition to has just blamed types “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert ainsi que al., 2012 ) for each were just one remote enamel which was the cornerstone to possess its particular medical diagnosis. Lately, Heckert mais aussi al. ( 2012 ) identified the fresh genus Revueltosaurus (spanning R. callenderi, R. hunti, and you can Roentgen. olseni) utilising the adopting the blend of character states: size (tooth crowns whenever 7 in order to 15-mm significant); several small denticles (over 7 for each carina) that are counterbalance (sub-perpendicular) with the enamel margin; denticles proportionately small and frequently worn towards the tooth because of the right occlusion; not enough a true cingulum; premaxillary enamel crowns that will be up to two times as tall as the maxillary/dentary tooth crowns and you will weakly recurved; and you will maxillary/dentary tooth crowns phyllodont (leaf-shaped). grams., Ezcurra, 2016 ). Such as for example, the blend of the sized one’s teeth, exactly how many the denticles, and also the positioning of your denticles convergence along with other distantly associated taxa (e.g., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn ainsi que al., 2010 ). The type “denticles proportionately quick and frequently used towards tooth from the exact occlusion” lacks accuracy with respect to what’s felt “brief,” in addition to wear pattern is tough so you’re able to exclude various other taxa and you may depends on a certain period of enamel in substitute for course (we.elizabeth., young white teeth would not be diagnosable as there wouldn’t be worn). Additionally, its lack of apomorphic character says (elizabeth.g., absence of cingulum) shouldn’t be used in an analysis, because they are symplesiomorphies. As well, the fresh project out of enamel condition according to one tooth (e.grams., premaxillary enamel crowns was whenever two times as high due to the fact maxillary/dentary enamel crowns and you will weakly recurved; maxillary/dentary tooth crowns leaf shaped) can’t be calculated regarding brand new sort of question, and also with more pearly whites on the same area, simply craniodental thing with pearly whites offer the association from enamel contour and you will tooth updates. Thus, the fresh new suggested tooth standing of holotype white teeth away from K. hunti and P. olseni is thought based on an enthusiastic inferred intimate reference to Roentgen. callenderi, which is known out of craniodental topic having teeth (discover a lot more than). In conclusion, the new genus Revueltosaurus sensu lato can’t be effectively and you will sustainably diagnosed in line with the style of product from R. callenderi, K. hunti, and P. olseni and we thus maximum the latest genus to one types, R. callenderi. As a result, i suggest https://datingranking.net/tr/aisle-inceleme that “R”. hunti take care of the subjective junior synonym Krzyzanowskisaurus hunti because the erected from the Heckert ( 2005 ) and you will “R”. olseni take care of the subjective older synonym Pekinosaurus olseni. I further caution the newest task of any present isolated tooth taxa to help you Revueltosaurus.
I do keep in mind that in the future, with done issue, Roentgen. callenderi, Krzyzanowskisaurus hunti, and you can Pekinosaurus olseni will get depict a monophyletic genus Revueltosaurus, however, an assignment of all of the three varieties to 1 genus is not already you can easily since it renders an a priori presumption in the dating (pick below) that’s parallel on the new argument that the Revueltosaurus white teeth have been assignable so you’re able to Ornithischia in the first place. This could has unwanted flowing consequences towards further macroevolutionary knowledge (elizabeth.grams., biogeography and paleocology). As an alternative, it is very quite possible these taxa may turn aside getting distantly relevant.
6.2.dos What is actually Krzyzanowskisaurus hunti?
Heckert ( 2002 ) revealed “Revueltosaurus” hunti, later assigned to the newest genus Krzyzanowskisaurus (Heckert, 2005 ), considering separated teeth throughout the Los Esteros Member of the newest Santa Rosa Creation (Dockum Class) in the main The fresh new Mexico and Bluish Mesa Person in new Chinle Creation into the eastern Washington (form of area off A beneficial. geoffreyi-see ), and it has been already acknowledged on lower Chinle Formation inside southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti pearly whites is famous away from Roentgen. callenderi white teeth by the exposure off a good ridge (“cingulum”) on the bottom of the tooth crown, hence connects towards carinae which will be often denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, et al., 2007 ; Data 14a, b). To start with, Krzyzanowskisaurus was entitled considering the different morphology of one’s white teeth between both versions and the disagreement the Krzyzanowskisaurus white teeth however have been assignable to an ornithischian rather than good pseudosuchian (Heckert, 2005 ). Irmis, Parker, et al. ( 2007 ) disagreed into the assignment off Krzyzanowskisaurus hunti to your Ornithischia oriented for the comparable arguments detailing the difficulties out-of delegating separated pearly whites so you can ornithischians as presented in the past as well as the framework you to definitely Heckert ( 2002 , 2005 ) identified as an effective “cingulum” wasn’t homologous with similar structures when you look at the ornithischian dinosaurs. Additionally, Irmis, Parker, ainsi que al. ( 2007 ) and listed you to an excellent Revueltosaurus-like squamosal, quadrate, and you may osteoderms was in fact and additionally available at an equivalent Washington locality once the Krzyzanowskisaurus hunti pearly whites, exactly as had took place at form of locality having Roentgen. callenderi (See ainsi que al., 2005 ).