six.dos.step one Diagnosing the Genus Revueltosaurus
The fresh new holotypes away from Roentgen. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), therefore the has just charged types “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert et al., 2012 ) each happened to be one separated enamel which had been the basis having the particular diagnosis. Most recently, Heckert mais aussi al. ( 2012 ) identified the newest genus Revueltosaurus (spanning R. callenderi, R. hunti, and Roentgen. olseni) utilizing the after the mix of reputation says: size (tooth crowns up to seven in order to 15-mm tall); numerous short denticles (more than 7 for every carina) which might be counterbalance (sub-perpendicular) toward tooth margin; denticles proportionately quick and frequently used on the tooth because of the direct occlusion; lack of a true cingulum; premaxillary tooth crowns which might be everything two times as tall since maxillary/dentary enamel crowns and you will weakly recurved; and you may maxillary/dentary enamel crowns phyllodont (leaf-shaped). g., Ezcurra, 2016 ). Such as for example, the mixture of your size of one’s teeth, what number of the fresh denticles, together with direction of your denticles overlap along with bunu kaz other distantly related taxa (age.grams., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn et al., 2010 ). The smoothness “denticles proportionately small and regularly used for the tooth of the accurate occlusion” lacks reliability when it comes to what exactly is considered “quick,” in addition to don development is hard to rule out various other taxa and you will hinges on a specific ages of tooth for the substitute for stage (we.elizabeth., young teeth would not be diagnosable because there would not be worn). Furthermore, its lack of apomorphic reputation claims (elizabeth.grams., absence of cingulum) shouldn’t be used in an analysis, since they are symplesiomorphies. At exactly the same time, the newest project regarding enamel reputation predicated on one tooth (e.g., premaxillary enamel crowns was just as much as doubly high due to the fact maxillary/dentary tooth crowns and you may weakly recurved; maxillary/dentary enamel crowns leaf designed) can’t be determined throughout the totally new kind of issue, as well as with more white teeth from the exact same locality, merely craniodental question having white teeth can provide new association regarding enamel figure and you will tooth status. Therefore, the fresh advised enamel condition of your holotype white teeth regarding K. hunti and you can P. olseni is assumed predicated on an inferred intimate relationship with R. callenderi, that is recognized off craniodental point with teeth (get a hold of significantly more than). To close out, the latest genus Revueltosaurus sensu lato cannot be effectively and you will sustainably diagnosed according to research by the types of material away from Roentgen. callenderi, K. hunti, and you may P. olseni and we for this reason limit the genus to 1 species, R. callenderi. As such, we propose that “R”. hunti take care of the personal junior word Krzyzanowskisaurus hunti once the erected because of the Heckert ( 2005 ) and you will “R”. olseni retain the subjective elderly synonym Pekinosaurus olseni. We subsequent alerting the fresh project of any existing remote tooth taxa to Revueltosaurus.
We manage realize that subsequently, with more over topic, Roentgen. callenderi, Krzyzanowskisaurus hunti, and you may Pekinosaurus olseni could possibly get depict a monophyletic genus Revueltosaurus, however, a project of the many about three variety to at least one genus is not currently you can easily because produces a the priori expectation throughout the matchmaking (look for lower than) which is parallel with the original conflict the Revueltosaurus pearly whites were assignable in order to Ornithischia before everything else. This could provides unwanted cascading effects into next macroevolutionary education (age.g., biogeography and you may paleocology). Alternatively, it is reasonably possible why these taxa may begin aside to-be distantly related.
6.dos.2 What is Krzyzanowskisaurus hunti?
Heckert ( 2002 ) revealed “Revueltosaurus” hunti, afterwards assigned to the new genus Krzyzanowskisaurus (Heckert, 2005 ), centered on remote white teeth throughout the Los Esteros Person in the brand new Santa Rosa Development (Dockum Class) inside main The Mexico and also the Bluish Mesa Person in new Chinle Formation inside east Washington (style of area away from A good. geoffreyi-come across ), and it has recently been recognized on straight down Chinle Creation during the southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti pearly whites is recognized of R. callenderi pearly whites by exposure away from a good ridge (“cingulum”) at the base of one’s enamel crown, and therefore connects with the carinae that’s have a tendency to denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, et al., 2007 ; Numbers 14a, b). In the first place, Krzyzanowskisaurus was called given the different morphology of one’s teeth between the 2 models therefore the argument that the Krzyzanowskisaurus white teeth still had been assignable to an enthusiastic ornithischian in the place of good pseudosuchian (Heckert, 2005 ). Irmis, Parker, mais aussi al. ( 2007 ) disagreed for the task from Krzyzanowskisaurus hunti to the Ornithischia dependent on the similar arguments describing the issues out of assigning isolated pearly whites so you can ornithischians because shown previously together with build you to definitely Heckert ( 2002 , 2005 ) recognized as a great “cingulum” was not homologous with the exact same structures for the ornithischian dinosaurs. Furthermore, Irmis, Parker, mais aussi al. ( 2007 ) in addition to listed one an excellent Revueltosaurus-particularly squamosal, quadrate, and osteoderms have been as well as available at the same Washington locality just like the Krzyzanowskisaurus hunti pearly whites, just as got taken place on sort of area to own Roentgen. callenderi (Have a look et al., 2005 ).
