6.2.1 Diagnosing the Genus Revueltosaurus
The holotypes regarding R. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), additionally the has just attributed varieties “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert et al., 2012 ) per had been a single isolated tooth which was the cornerstone getting the specific prognosis. Of late, Heckert et al. ( 2012 ) detected the brand new genus Revueltosaurus (spanning R. callenderi, R. hunti, and you will Roentgen. olseni) using the after the mixture of character claims: size (enamel crowns as much as 7 so you can fifteen-mm significant); multiple quick denticles (more than eight for each and every carina) that will be offset (sub-perpendicular) towards enamel margin; denticles proportionately small and sometimes used for the tooth by exact occlusion; diminished a genuine cingulum; premaxillary enamel crowns that will be as much as two times as high since the maxillary/dentary enamel crowns and you may weakly recurved; and you may maxillary/dentary enamel crowns phyllodont (leaf-shaped). grams., Ezcurra, 2016 ). Such as for example, the mixture of your own sized the teeth, what amount of the latest denticles, plus the direction of denticles overlap with other distantly relevant taxa (e.g., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn ainsi que al., 2010 ). The type “denticles proportionately short and often used towards tooth from the specific occlusion” does not have accuracy regarding what exactly is felt “small,” therefore the don trend is tough in order to eliminate various other taxa and you can relies on a particular age of enamel inside the substitute for duration (we.e., younger teeth wouldn’t be diagnosable as there would not be worn). In addition, its lack of apomorphic reputation states (age.g., lack of cingulum) really should not be used in an analysis, since they’re symplesiomorphies. On the other hand, the brand new project out-of enamel condition predicated on a single enamel (e.g., premaxillary enamel crowns are up to two times as high while the maxillary/dentary tooth crowns and you will weakly recurved; maxillary/dentary enamel crowns leaf formed) cannot be calculated regarding the new method of issue, and also with increased white teeth from the same locality, simply craniodental material having white teeth provide the newest relationship regarding tooth profile and you will enamel reputation. Therefore, the newest recommended tooth condition of your own holotype white teeth out of K. hunti and you may P. olseni is assumed predicated on an enthusiastic inferred romantic connection with R. callenderi, that’s understood out of craniodental point having white teeth (discover a lot more than). In conclusion, this new genus Revueltosaurus sensu lato can not be acceptably and you may sustainably diagnosed according to the style of content regarding Roentgen. callenderi, K. hunti, and you may P. olseni and we therefore limit the newest genus to a single variety, Roentgen. callenderi. Therefore, we propose that “R”. hunti retain the personal junior synonym Krzyzanowskisaurus hunti as erected by Heckert ( 2005 ) and you may “R”. olseni keep up with the personal elderly synonym Pekinosaurus olseni. We after that alerting the latest project of every established isolated enamel taxa to Revueltosaurus.
I carry out understand that later, with over situation, Roentgen. callenderi, Krzyzanowskisaurus hunti, and you can Pekinosaurus olseni may represent an excellent monophyletic genus Revueltosaurus, however, a task of all around three types to just one genus isn’t already you are able to because it renders a the priori expectation from the relationships (pick lower than) which is parallel on unique argument your Revueltosaurus pearly whites was indeed assignable so you’re able to Ornithischia first off. This may has undesirable streaming consequences with the then macroevolutionary training (elizabeth.grams., biogeography and you may paleocology). Alternatively, it is also possible that these taxa may start aside to-be distantly associated.
six http://www.datingranking.net/tr/daf-inceleme/.2.dos What is actually Krzyzanowskisaurus hunti?
Heckert ( 2002 ) discussed “Revueltosaurus” hunti, later on allotted to this new genus Krzyzanowskisaurus (Heckert, 2005 ), based on remote white teeth regarding the Los Esteros Person in new Santa Rosa Formation (Dockum Classification) during the main The Mexico additionally the Blue Mesa Member of brand new Chinle Formation in eastern Arizona (form of locality from Good. geoffreyi-discover ), and it has been recently accepted on the straight down Chinle Formation when you look at the southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti pearly whites is popular of Roentgen. callenderi teeth from the exposure of good ridge (“cingulum”) on the bottom of your own tooth top, and that connects towards carinae and that’s tend to denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, et al., 2007 ; Data 14a, b). To start with, Krzyzanowskisaurus are called considering the disparate morphology of one’s pearly whites anywhere between both versions and the conflict your Krzyzanowskisaurus teeth nonetheless had been assignable in order to an enthusiastic ornithischian instead of a good pseudosuchian (Heckert, 2005 ). Irmis, Parker, ainsi que al. ( 2007 ) disagreed towards the task out of Krzyzanowskisaurus hunti with the Ornithischia centered on the comparable arguments describing the problems of assigning isolated pearly whites to help you ornithischians since demonstrated in past times while the framework one Heckert ( 2002 , 2005 ) identified as a “cingulum” wasn’t homologous with the same structures inside the ornithischian dinosaurs. Furthermore, Irmis, Parker, mais aussi al. ( 2007 ) also detailed one a great Revueltosaurus-such as for example squamosal, quadrate, and osteoderms had been along with available at a comparable Washington area because Krzyzanowskisaurus hunti teeth, just as got took place during the sort of locality to own Roentgen. callenderi (Take a look ainsi que al., 2005 ).