6.dos.1 Diagnosis brand new Genus Revueltosaurus
The new holotypes away from Roentgen. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), plus the has just blamed species “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert mais aussi al., 2012 ) for every were just one remote enamel which had been the foundation for its particular diagnosis. Of late, Heckert ainsi que al. ( 2012 ) diagnosed the fresh genus Revueltosaurus (comprising Roentgen. callenderi, Roentgen. hunti, and R. olseni) making use of the after the blend of profile states: size (tooth crowns as much as 7 so you can 15-mm tall); numerous small denticles (more than eight for each carina) which can be offset (sub-perpendicular) to the enamel margin; denticles proportionately brief and sometimes used into tooth by the perfect occlusion; lack of a genuine cingulum; premaxillary enamel crowns which might be around twice as tall once the maxillary/dentary tooth crowns and weakly recurved; and you can maxillary/dentary enamel crowns phyllodont (leaf-shaped). grams., Ezcurra, 2016 ). For example, the blend of size of one’s teeth, exactly how many brand new denticles, additionally the direction of your own denticles overlap together with other distantly relevant taxa (e.g., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn ainsi que al., 2010 ). The character “denticles proportionately short and often worn to your tooth of the appropriate occlusion” lacks precision with respect to what’s sensed “brief,” and also the wear trend is difficult in order to eliminate in other taxa and you will depends on a certain chronilogical age of tooth during the replacement duration (i.elizabeth., more youthful pearly whites wouldn’t be diagnosable as there wouldn’t be worn). Furthermore, the absence of apomorphic character says (age.g., lack of cingulum) really should not be used in an analysis, since they’re symplesiomorphies. Simultaneously, this new task off tooth standing centered on an individual enamel (age.grams., premaxillary enamel crowns is approximately doubly significant because maxillary/dentary enamel crowns and you can weakly recurved; maxillary/dentary enamel crowns leaf molded) can not be calculated on the fresh method of question, plus with increased teeth regarding the exact same locality, only craniodental thing which have teeth also have brand new association of tooth shape and enamel updates. Therefore, the fresh new suggested enamel position of holotype teeth out of K. hunti and P. olseni is assumed according to an enthusiastic inferred intimate experience of R. callenderi, that’s recognized out-of craniodental question with white teeth (come across over). In conclusion, this new genus Revueltosaurus sensu lato can’t be acceptably and you can sustainably diagnosed according to research by the form of information out of Roentgen. callenderi, K. hunti, and you may P. olseni therefore for this reason limitation the latest genus to at least one species, R. callenderi. Therefore, we suggest that “R”. hunti maintain the subjective junior synonym Krzyzanowskisaurus hunti given that erected from the Heckert ( 2005 ) and you can “R”. olseni maintain the personal elder word Pekinosaurus olseni. We next caution the newest assignment of every current remote enamel taxa to help you Revueltosaurus.
I manage recognize that down the road, with increased done matter, R. callenderi, Krzyzanowskisaurus hunti, and you can Pekinosaurus olseni could possibly get portray a monophyletic genus Revueltosaurus, but a task of all three types to at least one genus is not currently possible because https://datingranking.net/tr/cupid-inceleme/ produces an a priori expectation throughout the dating (find less than) that is parallel with the modern dispute your Revueltosaurus white teeth have been assignable to help you Ornithischia to start with. This might has unwelcome streaming outcomes towards subsequent macroevolutionary knowledge (age.grams., biogeography and you will paleocology). Alternatively, it’s very quite possible that these taxa may begin away to-be distantly associated.
6.dos.dos What is actually Krzyzanowskisaurus hunti?
Heckert ( 2002 ) explained “Revueltosaurus” hunti, afterwards allotted to the fresh new genus Krzyzanowskisaurus (Heckert, 2005 ), centered on separated white teeth in the Los Esteros Member of the new Santa Rosa Creation (Dockum Class) from inside the central The newest Mexico additionally the Bluish Mesa Member of the fresh Chinle Formation during the east Washington (form of area regarding An effective. geoffreyi-get a hold of ), and contains already been recognized on the down Chinle Formation from inside the southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti teeth was celebrated off Roentgen. callenderi pearly whites from the exposure away from an excellent ridge (“cingulum”) at the base of one’s tooth top, which connects toward carinae that is will denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, mais aussi al., 2007 ; Figures 14a, b). To begin with, Krzyzanowskisaurus are named considering the different morphology of your teeth between both models plus the disagreement the Krzyzanowskisaurus white teeth nevertheless have been assignable in order to an enthusiastic ornithischian in lieu of a beneficial pseudosuchian (Heckert, 2005 ). Irmis, Parker, et al. ( 2007 ) disagreed into project out-of Krzyzanowskisaurus hunti towards Ornithischia depending into comparable arguments describing the difficulties out of assigning remote white teeth so you can ornithischians while the presented before plus the design one to Heckert ( 2002 , 2005 ) defined as an excellent “cingulum” wasn’t homologous with similar structures in ornithischian dinosaurs. Furthermore, Irmis, Parker, mais aussi al. ( 2007 ) as well as noted you to good Revueltosaurus-such as for instance squamosal, quadrate, and osteoderms was in fact as well as available at an identical Washington area due to the fact Krzyzanowskisaurus hunti teeth, exactly as had occurred during the method of area for R. callenderi (Appear mais aussi al., 2005 ).