2 GEOLOGICAL Means
None Parker mais aussi al. ( 2005 ) nor Have a look mais aussi al. ( 2005 ) experimented with a beneficial phylogenetic study from R. callenderi according to research by the brand new skeletal procedure. But not, each other communities indexed several top features of the newest hindlimb that have been unambiguous synapomorphies out-of Pseudosuchia. Parker mais aussi al. ( 2005 ) hypothesized a possible cousin-category reference to aetosaurs, noting new morphological similarities of one’s squamosal and you may paramedian osteoderms. An equivalent condition is advised because of the Have a look mais aussi al. ( 2005 ) centered on unspecified character states of one’s tarsus while the osteoderms. Brusatte mais aussi al. ( 2010 ) integrated R. callenderi in their investigation regarding early beautifulpeople ne demek archosaur relationship, programming regarding the wrote data and you can meanings away from Parker mais aussi al. ( 2005 ) and you will Look mais aussi al. ( 2005 ). You to data retrieved R. callenderi since aunt taxon toward very early-diverging suchian clade Ornithosuchidae. ( 2011 ) recovered Roentgen. callenderi within the a properly-served reputation just like the sis taxon so you’re able to aetosaurs, an end result backed by more recent education (e.grams., Butler et al., 2014 ; ; Nesbitt & Butler, 2013 ; Nesbitt mais aussi al., 2014 ; Nesbitt et al., 2020 ; Nesbitt, Stocker, mais aussi al., 2018 ).
It share totally makes reference to the brand new osteology off Roentgen. callenderi based on at least 12 individuals (predicated on femora count) of PEFO as well as around three better-managed relevant limited skeletons collected anywhere between 2005 and you will 2015, brings osteohistological perspective, and you can discusses the latest taxon’s advantages to have facts very early suchian evolution.
2.step one Stratigraphic updates
That it description out of R. callenderi is actually mainly according to procedure from numerous localities in the Chinle Formation out-of Petrified Forest Federal Playground (PEFO), Arizona, United states (Profile step 1; see Medical Paleontology). The upper Triassic Chinle Creation in this area constitutes mostly fluvial and you may floodplain strata away from changing claystones, siltstones, sandstones, and you may conglomerates (Billingsley, 1985 ; Heckert & Lucas, 2002a ; ). The latest Chinle Formation in the Petrified Tree National Park urban area preserves well-identified fossil assemblages of plants (palynomorphs, simply leaves, wood), invertebrates, and you can vertebrates (e.grams., Ash, 2005 ; Baranyi mais aussi al., 2018 ; Good, 1998 ; Irmis, 2005 ; Litwin, Navigate, & Ash, 1991 ; Parker, 2005b , 2006 ; Reichgelt et al., 2013 ). Extremely non-dentigerous and you will low-osteoderm specimens regarding Roentgen. callenderi out of PEFO, and additionally men and women discussed right here, have been found immediately more than Coated Desert Sandstone 3 (sensu Billingsley, 1985 ; Lithodendron Clean Sleep sensu Heckert & Lucas, 2002a ) in the middle a portion of the Petrified Forest Affiliate (sensu Woody, 2006 ) of your higher part of the Chinle Formation (Heckert & Lucas, 2002a ; Irmis, 2005 ; Padian, 1990 ; Parker, 2005b , 2006 ; Parker ainsi que al., 2005 ; Parker & ). Remote teeth of Roentgen. callenderi have been recovered out-of microvertebrate assemblages from reduced in this new Chinle Development within PEFO, stretching brand new stratigraphic selection of that it taxon to your Sonsela User and uppermost Blue Mesa Associate (look for Medical Paleontology).
The 3 main localities you to definitely put this new specimens away from Roentgen. callenderi revealed right here (Research S1) may be the Revueltosaurus Quarry (PFV 297), Revueltosaurus Quarry SW (PFV 414), and the Giving Webpages (PFV 231). Those sites are present because the paleosols during the a piled fluvial succession in the middle of the newest Petrified Forest Member (Atchley mais aussi al., 2013 ; Loughney ainsi que al., 2011 ; Parker ainsi que al., 2005 ; Parker & ). PFV 297 and you will PFV 414 try split spatially by 20 meters and therefore are in turn on the 200 meters with the the southern part of out of PFV 231 (Contour 1a). Painted Desert Sandstone 3, and therefore quickly underlies all three localities, try stratigraphically
40–50 yards over the foot of the Petrified Forest Affiliate (Shape 1b; Parker & ), and you will represents a sheet sandstone transferred by perennial circulate during the an excellent highest sinuosity lake route (Johns, 1988 ). PFV 297 and you can PFV 414 occur a bit highest about succession than PFV 231 (Parker & ).