six.dos.step one Diagnosis the fresh new Genus Revueltosaurus
The new holotypes out-of Roentgen. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), therefore the recently attributed species “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert et al., 2012 ) for each and every were a single isolated tooth that was the cornerstone to own the specific diagnosis. Lately, Heckert et al. ( 2012 ) recognized brand new genus Revueltosaurus (comprising Roentgen. callenderi, R. hunti, and you will R. olseni) using the adopting the mixture of profile claims: proportions (tooth crowns just as much as 7 to help you fifteen-mm extreme); multiple quick denticles (more than eight each carina) which might be counterbalance (sub-perpendicular) to your enamel margin; denticles proportionately brief and often used on the tooth because of the precise occlusion; decreased a real cingulum; premaxillary enamel crowns that are up to twice as high since maxillary/dentary enamel crowns and you will weakly recurved; and you will maxillary/dentary tooth crowns phyllodont (leaf-shaped). g., Ezcurra, 2016 ). Such, the combination of the sized the teeth, what number of this new denticles, and the orientation of your own denticles convergence together with other distantly related taxa (e.grams., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn et al., 2010 ). The smoothness “denticles proportionately brief and often used into enamel by the specific occlusion” does not have reliability in terms of what is felt “brief,” while the wear pattern is tough so you’re able to eliminate in other taxa and you will relies on a specific age tooth when you look at the replacement duration (we.e., more youthful white teeth would not be diagnosable since there wouldn’t be worn). In addition, its lack of apomorphic profile states (age.g., lack of cingulum) shouldn’t be utilized in a diagnosis, since they are symplesiomorphies. Additionally, the brand new project out of tooth position according to a single tooth (elizabeth.grams., premaxillary tooth crowns is actually approximately two times as high once the maxillary/dentary enamel crowns and you can weakly recurved; maxillary/dentary enamel crowns leaf designed) can’t be determined throughout the new type of thing, as well as with more teeth regarding the exact same locality, merely craniodental topic with white teeth provide the connection from tooth contour and you may tooth condition. Thus, the new recommended enamel standing of holotype pearly whites away from K. hunti and you can P. olseni is believed considering an inferred romantic connection with R. callenderi, which is understood of craniodental procedure that have white teeth (select a lot more than) chatspin mesajlaЕџma. To close out, the latest genus Revueltosaurus sensu lato can’t be acceptably and you may sustainably recognized in line with the style of material off Roentgen. callenderi, K. hunti, and you may P. olseni and now we ergo limitation the genus to at least one types, Roentgen. callenderi. As such, we suggest that “R”. hunti take care of the personal junior word Krzyzanowskisaurus hunti because erected from the Heckert ( 2005 ) and you will “R”. olseni keep up with the personal senior word Pekinosaurus olseni. We after that caution the fresh task of any present remote enamel taxa so you can Revueltosaurus.
We create understand that subsequently, with over material, Roentgen. callenderi, Krzyzanowskisaurus hunti, and you will Pekinosaurus olseni get depict good monophyletic genus Revueltosaurus, but a project of all the around three species to 1 genus isn’t already you are able to since it produces an one priori assumption regarding relationship (look for lower than) that is synchronous for the amazing argument the Revueltosaurus pearly whites was basically assignable to help you Ornithischia to start with. This could enjoys undesired flowing effects for the further macroevolutionary studies (age.g., biogeography and you can paleocology). As an alternative, it’s very possible that these taxa may turn aside to get distantly related.
6.dos.dos What is actually Krzyzanowskisaurus hunti?
Heckert ( 2002 ) described “Revueltosaurus” hunti, after allotted to the latest genus Krzyzanowskisaurus (Heckert, 2005 ), predicated on isolated white teeth about Los Esteros Person in the latest Santa Rosa Development (Dockum Class) into the main The fresh new Mexico and also the Bluish Mesa Member of new Chinle Creation for the east Arizona (sorts of locality of A beneficial. geoffreyi-pick ), and contains been recently recognized from the down Chinle Creation inside the southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti pearly whites are distinguished out of Roentgen. callenderi pearly whites because of the visibility away from good ridge (“cingulum”) on the bottom of the tooth crown, and therefore connects into carinae that’s commonly denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, et al., 2007 ; Numbers 14a, b). Originally, Krzyzanowskisaurus is called given the disparate morphology of white teeth between the two variations plus the dispute the Krzyzanowskisaurus pearly whites however was assignable to an ornithischian instead of a great pseudosuchian (Heckert, 2005 ). Irmis, Parker, et al. ( 2007 ) disagreed on the assignment out of Krzyzanowskisaurus hunti to the Ornithischia oriented to the similar arguments describing the difficulties of delegating isolated teeth to help you ornithischians while the presented prior to now and build one to Heckert ( 2002 , 2005 ) identified as a great “cingulum” was not homologous with similar structures inside the ornithischian dinosaurs. Additionally, Irmis, Parker, et al. ( 2007 ) in addition to noted you to definitely a good Revueltosaurus-such as for example squamosal, quadrate, and you can osteoderms had been and available at an identical Arizona area as Krzyzanowskisaurus hunti white teeth, just as got took place in the sort of area to have Roentgen. callenderi (Have a look ainsi que al., 2005 ).