6.2.step one Diagnosis the new Genus Revueltosaurus
The latest holotypes from R. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), plus the recently charged varieties “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert ainsi que al., 2012 ) each were just one separated tooth that has been the cornerstone having their certain diagnosis. Most recently, Heckert et al. ( 2012 ) identified the newest genus Revueltosaurus (spanning Roentgen. callenderi, Roentgen. hunti, and you can Roentgen. olseni) by using the following the mix of character states: dimensions (enamel crowns whenever 7 in order to fifteen-mm significant); several small denticles (more 7 for each and every carina) which might be offset (sub-perpendicular) to your tooth margin; denticles proportionately brief and regularly used on the enamel by exact occlusion; lack of a genuine cingulum; premaxillary enamel crowns that will be just as much as doubly significant as maxillary/dentary enamel crowns and you may weakly recurved; and you can maxillary/dentary enamel crowns phyllodont (leaf-shaped). grams., Ezcurra, 2016 ). Such as, the mixture of your own measurements of tooth, the amount of the latest denticles, in addition to positioning of denticles overlap along with other distantly relevant taxa (elizabeth.g., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn et al., 2010 ). The character “denticles http://datingranking.net/tr/interracial-dating-central-inceleme/ proportionately short and often used with the enamel because of the exact occlusion” does not have reliability regarding what is considered “quick,” in addition to don trend is difficult so you can exclude in other taxa and you can depends on a certain age of tooth inside replacement duration (i.elizabeth., young pearly whites wouldn’t be diagnosable since there would not be worn). Furthermore, its lack of apomorphic character says (e.grams., lack of cingulum) really should not be included in a diagnosis, since they are symplesiomorphies. Concurrently, the new task away from enamel position according to just one tooth (age.g., premaxillary tooth crowns is actually just as much as two times as tall as maxillary/dentary tooth crowns and you will weakly recurved; maxillary/dentary tooth crowns leaf molded) cannot be determined regarding the brand new method of procedure, plus with an increase of pearly whites regarding same locality, merely craniodental matter having pearly whites can provide the new association out of enamel figure and you may tooth standing. Hence, this new advised tooth position of the holotype white teeth out-of K. hunti and you will P. olseni is believed considering an inferred close experience of R. callenderi, that is recognized out-of craniodental topic having white teeth (select a lot more than). In conclusion, this new genus Revueltosaurus sensu lato cannot be properly and you can sustainably diagnosed in accordance with the form of content out of R. callenderi, K. hunti, and P. olseni so we hence restrict brand new genus to one species, R. callenderi. Therefore, we propose that “R”. hunti maintain the personal junior word Krzyzanowskisaurus hunti once the erected by Heckert ( 2005 ) and you will “R”. olseni take care of the subjective older synonym Pekinosaurus olseni. I subsequent warning the fresh new task of any present remote enamel taxa so you can Revueltosaurus.
We would understand that in the future, with more done material, R. callenderi, Krzyzanowskisaurus hunti, and you can Pekinosaurus olseni may portray a good monophyletic genus Revueltosaurus, but an assignment of all about three kinds to 1 genus is not already you’ll since it produces an one priori expectation on the matchmaking (find less than) which is synchronous to your new argument your Revueltosaurus pearly whites have been assignable so you’re able to Ornithischia before everything else. This might possess undesired streaming outcomes on the next macroevolutionary knowledge (e.grams., biogeography and you can paleocology). Rather, it is very quite possible these taxa may begin away getting distantly associated.
six.dos.dos What exactly is Krzyzanowskisaurus hunti?
Heckert ( 2002 ) discussed “Revueltosaurus” hunti, later on assigned to the genus Krzyzanowskisaurus (Heckert, 2005 ), predicated on isolated white teeth regarding Los Esteros Person in new Santa Rosa Formation (Dockum Category) in central The brand new Mexico in addition to Bluish Mesa Person in the latest Chinle Creation within the east Washington (sorts of locality off A good. geoffreyi-get a hold of ), and has now recently been accepted about all the way down Chinle Creation within the southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti pearly whites try notable from R. callenderi white teeth because of the presence regarding an effective ridge (“cingulum”) on the bottom of tooth top, and this links for the carinae and is usually denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, mais aussi al., 2007 ; Numbers 14a, b). In the first place, Krzyzanowskisaurus try named given the disparate morphology of your own teeth ranging from the 2 variations as well as the argument your Krzyzanowskisaurus pearly whites however were assignable to help you a keen ornithischian instead of an effective pseudosuchian (Heckert, 2005 ). Irmis, Parker, ainsi que al. ( 2007 ) disagreed to your project out-of Krzyzanowskisaurus hunti toward Ornithischia situated toward comparable objections discussing the problems off delegating remote teeth so you can ornithischians since showed in the past together with framework one Heckert ( 2002 , 2005 ) identified as an excellent “cingulum” was not homologous with the same structures from inside the ornithischian dinosaurs. Also, Irmis, Parker, mais aussi al. ( 2007 ) including listed you to good Revueltosaurus-for example squamosal, quadrate, and osteoderms was basically and additionally bought at the same Arizona area because Krzyzanowskisaurus hunti teeth, exactly as got happened on form of locality having R. callenderi (Look mais aussi al., 2005 ).