6.dos.step one Diagnosing the fresh Genus Revueltosaurus
The latest holotypes from R. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), in addition to recently charged species “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert mais aussi al., 2012 ) for each are an individual isolated enamel which had been the cornerstone to own its particular analysis. Of late, Heckert ainsi que al. ( 2012 ) identified the newest genus Revueltosaurus (spanning R. callenderi, R. hunti, and you can R. olseni) with the following mixture of reputation states: size (tooth crowns as much as seven so you’re able to 15-mm significant); several brief denticles (more eight for each and every carina) that are counterbalance (sub-perpendicular) into tooth margin; denticles proportionately short and frequently used for the tooth from the accurate occlusion; decreased a true cingulum; premaxillary tooth crowns that will be whenever doubly significant due to the fact maxillary/dentary enamel crowns and you may weakly recurved; and maxillary/dentary enamel crowns phyllodont (leaf-shaped). g., Ezcurra, 2016 ). Such as for example, the mixture of your sized tooth, what number of the latest denticles, while the direction of denticles overlap along with other distantly related taxa (age.g., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn et al., 2010 ). The type “denticles proportionately small and sometimes used for the tooth by the particular occlusion” lacks precision regarding what’s experienced “quick,” in addition to wear development is hard to help you eliminate in other taxa and you will depends on a specific ages of enamel inside substitute for duration (i.elizabeth., younger pearly whites would not be diagnosable as there wouldn’t be worn). Additionally, its lack of apomorphic character states (elizabeth.grams., absence of cingulum) should not be found in an analysis, since they’re symplesiomorphies. Likewise, the brand new task off tooth condition considering a single tooth (elizabeth.g., premaxillary enamel crowns try whenever doubly high just like the maxillary/dentary enamel crowns and you may weakly recurved; maxillary/dentary enamel crowns leaf designed) can not be calculated on the completely new particular procedure, plus with an increase of pearly whites on the same locality, merely craniodental question having teeth provide this new connection regarding tooth figure and you can tooth reputation. Ergo, this new advised tooth condition of the holotype teeth regarding K. hunti and you may P. olseni is thought predicated on an enthusiastic inferred close connection with R. callenderi, that is identified away from craniodental situation that have white teeth (discover a lot more than). To conclude, the fresh genus Revueltosaurus sensu lato can’t be properly and you can sustainably diagnosed in line with the particular material out of Roentgen. callenderi, K. hunti, and P. olseni so we therefore limitation new genus to at least one varieties, Roentgen. callenderi. Therefore, i suggest that “R”. hunti keep up with the subjective junior synonym Krzyzanowskisaurus hunti because the erected because of the Heckert ( 2005 ) and you may “R”. olseni keep up with the subjective elderly synonym Pekinosaurus olseni. We next caution brand new assignment of any established remote tooth taxa to help you Revueltosaurus.
We perform realize that later on, with more done thing, Roentgen. callenderi, Krzyzanowskisaurus hunti, and you can Pekinosaurus olseni may show a monophyletic genus Revueltosaurus, however, an assignment of the many around three kinds to just one genus is not currently it is possible to because can make a the priori assumption in the matchmaking (come across less than) that’s synchronous on totally new argument that the Revueltosaurus pearly whites was indeed assignable to Ornithischia before everything else. This might have undesired flowing outcomes into the subsequent macroevolutionary degree (elizabeth.g., biogeography and you may paleocology). Alternatively, it is also possible that these taxa may turn away to be distantly relevant.
six.2.dos What’s Krzyzanowskisaurus hunti?
Heckert ( 2002 ) explained “Revueltosaurus” hunti, after assigned to brand new genus Krzyzanowskisaurus (Heckert, 2005 ), centered on separated teeth on Los Esteros Person in the fresh new Santa Rosa Formation (Dockum Classification) during the main The fresh new Mexico and Blue Mesa Person in the fresh new Chinle Formation within the eastern Arizona (sorts of area of An effective. geoffreyi-select ), and it has recently been recognized about straight down Chinle Development during the southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti white teeth try distinguished off R. callenderi white teeth because of the exposure out-of an effective ridge (“cingulum”) on the bottom of your own tooth top, and therefore links towards the carinae that’s tend to denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, ainsi que al., 2007 ; Rates 14a, b). To start with, Krzyzanowskisaurus are named given the different morphology of your white teeth between the two versions together with dispute the Krzyzanowskisaurus teeth nevertheless was basically assignable to a keen ornithischian in lieu of an effective pseudosuchian (Heckert, 2005 ). Irmis, Parker, ainsi que al. ( 2007 ) connecting singles ne demek disagreed on project regarding Krzyzanowskisaurus hunti on Ornithischia oriented on the similar objections outlining the problems off delegating isolated white teeth in order to ornithischians due to the fact exhibited before and design you to definitely Heckert ( 2002 , 2005 ) defined as a “cingulum” wasn’t homologous with similar structures from inside the ornithischian dinosaurs. Furthermore, Irmis, Parker, et al. ( 2007 ) plus detailed you to definitely a good Revueltosaurus-particularly squamosal, quadrate, and you can osteoderms was in fact and available at a similar Arizona locality because Krzyzanowskisaurus hunti white teeth, just as had took place from the form of locality to have Roentgen. callenderi (Look et al., 2005 ).