six.2.step one Diagnosis the Genus Revueltosaurus
This new holotypes of R. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), together with recently attributed species “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert ainsi que al., 2012 ) for every had been one separated tooth which was the cornerstone getting their particular prognosis. Lately, Heckert et al. ( 2012 ) detected the new genus Revueltosaurus (spanning R. callenderi, R. hunti, and Roentgen. olseni) by using the adopting the combination of reputation states: dimensions (enamel crowns everything 7 in order to fifteen-mm significant); several brief denticles (more seven for each and every carina) which can be offset (sub-perpendicular) towards the tooth margin; denticles proportionately brief and frequently worn on tooth of the appropriate occlusion; shortage of a true cingulum; premaxillary enamel crowns that are approximately two times as significant because maxillary/dentary enamel crowns and you can weakly recurved; and maxillary/dentary enamel crowns phyllodont (leaf-shaped). g., Ezcurra, 2016 ). Such, the mixture of measurements of one’s teeth, the number of this new denticles, as well as the positioning of your own denticles overlap together with other distantly relevant taxa (e.g., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn mais aussi al., 2010 ). The smoothness “denticles proportionately brief and sometimes used to your tooth because of the perfect occlusion” lacks precision with respect to what is actually sensed “brief,” as well as the wear development is tough to exclude in other taxa and you can utilizes a certain age of tooth for the replacement for stage (we.age., younger pearly whites wouldn’t be diagnosable as there wouldn’t be worn). Furthermore, its lack of apomorphic profile claims (e.grams., lack of cingulum) really should not be utilized in an analysis, since they are symplesiomorphies. On the other hand, the latest task from enamel updates based on one tooth (age.g., premaxillary tooth crowns was everything doubly tall since maxillary/dentary enamel crowns and you may weakly recurved; maxillary/dentary enamel crowns leaf formed) can’t be calculated in the fresh kind of issue, plus with increased white teeth throughout the exact same locality, merely craniodental procedure having white teeth offer brand new organization from tooth contour and you can tooth standing. Ergo, the new suggested tooth position of your holotype teeth from K. hunti and you will P. olseni is believed according to an enthusiastic inferred personal relationship with R. callenderi, that’s understood regarding craniodental procedure which have pearly whites (see significantly more than). To conclude, the new genus Revueltosaurus sensu lato cannot be effectively and you can sustainably identified according to the type material regarding Roentgen. callenderi, K. hunti, and you can P. olseni and then we ergo limit the brand new genus to a single species, R. callenderi. As such, we suggest that “R”. hunti maintain the personal junior synonym Krzyzanowskisaurus hunti just like the erected of the Heckert ( 2005 ) and you may “R”. olseni maintain the subjective senior word Pekinosaurus olseni. I next alerting the brand new assignment of any current remote tooth taxa so you can Revueltosaurus.
I carry out keep in mind that in the future, with more complete material, Roentgen. callenderi, Krzyzanowskisaurus hunti, and you will Pekinosaurus olseni could possibly get show an excellent monophyletic genus Revueltosaurus, however, a task of the many about three kinds to 1 genus isn’t currently you are able to whilst renders an a priori expectation from the matchmaking (find below) that is parallel to your amazing conflict the Revueltosaurus white teeth had been assignable to help you Ornithischia before everything else. This could keeps undesirable cascading effects on next macroevolutionary degree (elizabeth.g., biogeography and you can paleocology). Rather, it’s very quite possible these particular taxa may turn away to-be distantly relevant.
six.2.2 What is actually Krzyzanowskisaurus hunti?
Heckert ( 2002 ) revealed “Revueltosaurus” hunti, after allotted to the fresh new genus Krzyzanowskisaurus (Heckert, 2005 ), considering remote pearly whites from the Los Esteros Person in the new Santa Rosa Development (Dockum Group) into the main The new Mexico and the Blue Mesa Person in the latest Chinle Development into the eastern Arizona (form of area out of Good. geoffreyi-discover ), possesses been recently approved on the down Chinle Formation in southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti pearly whites are well-known of Roentgen. callenderi white teeth of the visibility off an effective ridge (“cingulum”) toward the base of your tooth crown, hence connects for the carinae that is tend to denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, et al., 2007 ; Numbers 14a, b). In the first place, Krzyzanowskisaurus are entitled because of the disparate morphology of teeth between both variations therefore the argument that the Krzyzanowskisaurus teeth however was indeed assignable so you can an ornithischian as opposed to good pseudosuchian (Heckert, 2005 ). Irmis, Parker, mais aussi al. ( 2007 ) disagreed on the task from Krzyzanowskisaurus hunti to the Ornithischia built for the equivalent arguments outlining the difficulties out of assigning separated pearly whites so you’re able to ornithischians just like the showed previously and construction one Heckert ( 2002 , 2005 ) identified as an excellent “cingulum” wasn’t homologous with the same structures within the ornithischian dinosaurs. Additionally, Irmis, Parker, mais aussi al. ( 2007 ) as well as detailed you to an excellent Revueltosaurus-instance squamosal, quadrate, and osteoderms was in addition to available at an equivalent Arizona locality as Krzyzanowskisaurus hunti teeth, just as got taken place at method of area to have R. callenderi (Seem mais aussi al., 2005 ).