six.dos.1 Diagnosis the new Genus Revueltosaurus
The latest holotypes off R. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), while the has just charged variety “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert mais aussi al., 2012 ) for every happened to be an individual isolated enamel which was the cornerstone to own the particular diagnosis. Of late, Heckert ainsi que al. ( 2012 ) diagnosed the newest genus Revueltosaurus (spanning Roentgen. callenderi, R. hunti, and you can Roentgen. olseni) utilizing the after the blend of reputation claims: size (tooth crowns up to seven so you can 15-mm extreme); multiple small denticles (more eight for each and every carina) that are counterbalance (sub-perpendicular) into tooth margin; denticles proportionately brief and frequently used with the enamel by the precise occlusion; not enough a true cingulum; premaxillary enamel crowns that will be approximately two times as extreme once the maxillary/dentary tooth crowns and you may weakly recurved; and you can maxillary/dentary enamel crowns phyllodont (leaf-shaped). grams., Ezcurra, 2016 ). Instance, the mixture of the sized the teeth, what amount of brand new denticles, while the direction of your denticles overlap together with other distantly associated taxa (e.g., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn et al., 2010 ). The character “denticles proportionately quick and frequently used to the enamel by the specific occlusion” lacks accuracy regarding what’s noticed “quick,” in addition to don development is tough in order to exclude various other taxa and you can depends on a specific age of enamel into the replacement stage (i.e. datingranking.net/tr/chinalovecupid-inceleme, younger white teeth wouldn’t be diagnosable since there wouldn’t be worn). Also, the absence of apomorphic character claims (elizabeth.g., lack of cingulum) really should not be used in an analysis, as they are symplesiomorphies. Likewise, the brand new task regarding tooth condition according to one enamel (e.g., premaxillary enamel crowns is actually as much as twice as high as maxillary/dentary tooth crowns and you will weakly recurved; maxillary/dentary enamel crowns leaf designed) cannot be computed on the unique type procedure, and also with additional teeth regarding the exact same locality, just craniodental procedure having teeth offer new connection from tooth shape and you may enamel updates. Therefore, new suggested enamel standing of your own holotype white teeth away from K. hunti and P. olseni is thought based on a keen inferred close connection with Roentgen. callenderi, which is understood from craniodental point which have white teeth (discover more than). To summarize, the fresh genus Revueltosaurus sensu lato can’t be properly and sustainably identified in line with the types of information out of R. callenderi, K. hunti, and P. olseni and now we therefore maximum the genus to a single varieties, Roentgen. callenderi. As such, we suggest that “R”. hunti take care of the subjective junior word Krzyzanowskisaurus hunti while the erected because of the Heckert ( 2005 ) and you will “R”. olseni retain the personal older synonym Pekinosaurus olseni. I then alerting the fresh new project of any established isolated tooth taxa to help you Revueltosaurus.
We perform understand that later on, with an increase of complete matter, R. callenderi, Krzyzanowskisaurus hunti, and you can Pekinosaurus olseni can get depict a good monophyletic genus Revueltosaurus, however, a task of the many about three types to at least one genus is not already you’ll since it tends to make an a priori expectation regarding relationship (see lower than) that’s parallel toward amazing dispute your Revueltosaurus pearly whites had been assignable in order to Ornithischia first off. This may have undesired streaming effects into next macroevolutionary education (e.grams., biogeography and you may paleocology). As an alternative, it is extremely quite possible these taxa may turn away to get distantly relevant.
6.2.dos What exactly is Krzyzanowskisaurus hunti?
Heckert ( 2002 ) explained “Revueltosaurus” hunti, later allotted to the genus Krzyzanowskisaurus (Heckert, 2005 ), according to isolated teeth regarding Los Esteros Person in brand new Santa Rosa Creation (Dockum Category) for the central The new Mexico in addition to Blue Mesa Person in the fresh new Chinle Formation from inside the eastern Washington (kind of area of An excellent. geoffreyi-pick ), possesses recently been recognized about all the way down Chinle Creation for the southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti white teeth was known regarding Roentgen. callenderi white teeth by the presence out-of a ridge (“cingulum”) on the bottom of your own enamel crown, hence links with the carinae and is commonly denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, ainsi que al., 2007 ; Data 14a, b). To start with, Krzyzanowskisaurus try titled considering the disparate morphology of one’s pearly whites ranging from both models and also the disagreement that Krzyzanowskisaurus white teeth nevertheless was basically assignable so you’re able to an enthusiastic ornithischian in the place of an effective pseudosuchian (Heckert, 2005 ). Irmis, Parker, ainsi que al. ( 2007 ) disagreed to your task of Krzyzanowskisaurus hunti toward Ornithischia depending to your similar arguments discussing the problems out of assigning remote white teeth to ornithischians as displayed prior to now and also the structure one Heckert ( 2002 , 2005 ) recognized as good “cingulum” was not homologous with the exact same formations in ornithischian dinosaurs. Also, Irmis, Parker, ainsi que al. ( 2007 ) including noted that a good Revueltosaurus-instance squamosal, quadrate, and you may osteoderms had been plus found at the same Arizona locality while the Krzyzanowskisaurus hunti teeth, exactly as had taken place during the method of area getting Roentgen. callenderi (See ainsi que al., 2005 ).