dos GEOLOGICAL Function
Neither Parker ainsi que al. ( 2005 ) neither Search et al. ( 2005 ) experimented with a good phylogenetic study of Roentgen. callenderi in accordance with the the newest skeletal issue. However, one another communities noted numerous top features of the brand new hindlimb that were unambiguous synapomorphies from Pseudosuchia. Parker et al. ( 2005 ) hypothesized a prospective brother-group connection with aetosaurs, listing the fresh morphological similarities of one’s squamosal and you will paramedian osteoderms. An identical status are advised because of the Appear ainsi que al. ( 2005 ) predicated on abdlmatch giriЕџ unspecified profile claims of your tarsus and the osteoderms. Brusatte ainsi que al. ( 2010 ) integrated R. callenderi within data away from early archosaur relationship, coding throughout the published figures and you may descriptions of Parker et al. ( 2005 ) and you may Look et al. ( 2005 ). You to definitely study retrieved Roentgen. callenderi because aunt taxon towards the early-diverging suchian clade Ornithosuchidae. ( 2011 ) recovered R. callenderi when you look at the a well-served position because the aunt taxon so you’re able to aetosaurs, an effect backed by newer studies (age.grams., Butler et al., 2014 ; ; Nesbitt & Butler, 2013 ; Nesbitt mais aussi al., 2014 ; Nesbitt ainsi que al., 2020 ; Nesbitt, Stocker, ainsi que al., 2018 ).
This sum completely identifies the fresh osteology out-of Roentgen. callenderi centered on at least 12 some one (based on femora count) out of PEFO also three well-managed associated partial skeletons compiled between 2005 and 2015, brings osteohistological perspective, and you will covers the new taxon’s strengths to possess understanding very early suchian progression.
2.1 Stratigraphic status
That it description off R. callenderi is actually mainly considering issue out of multiple localities on the Chinle Formation out-of Petrified Tree National Playground (PEFO), Arizona, All of us (Profile step one; see Scientific Paleontology). The top of Triassic Chinle Creation in this area comprises predominantly fluvial and you can floodplain strata from alternating claystones, siltstones, sandstones, and you will conglomerates (Billingsley, 1985 ; Heckert & Lucas, 2002a ; ). The brand new Chinle Formation about Petrified Forest Federal Playground town conserves well-known traditional assemblages of plant life (palynomorphs, makes, wood), invertebrates, and you will vertebrates (age.g., Ash, 2005 ; Baranyi mais aussi al., 2018 ; Good, 1998 ; Irmis, 2005 ; Litwin, Navigate, & Ash, 1991 ; Parker, 2005b , 2006 ; Reichgelt ainsi que al., 2013 ). Very low-dentigerous and you will low-osteoderm specimens out of R. callenderi regarding PEFO, along with the individuals explained here, have been found quickly significantly more than Painted Desert Sandstone step 3 (sensu Billingsley, 1985 ; Lithodendron Wash Sleep sensu Heckert & Lucas, 2002a ) around area of the Petrified Forest Associate (sensu Woody, 2006 ) of the higher area of the Chinle Creation (Heckert & Lucas, 2002a ; Irmis, 2005 ; Padian, 1990 ; Parker, 2005b , 2006 ; Parker mais aussi al., 2005 ; Parker & ). Separated teeth out-of R. callenderi was recovered from microvertebrate assemblages of lower in the newest Chinle Development on PEFO, stretching the new stratigraphic listing of this taxon towards Sonsela Associate and uppermost Blue Mesa Affiliate (find Health-related Paleontology).
The three chief localities you to definitely introduced the fresh specimens out-of Roentgen. callenderi revealed here (Study S1) may be the Revueltosaurus Quarry (PFV 297), Revueltosaurus Quarry SW (PFV 414), in addition to Giving Webpages (PFV 231). The internet sites exist as paleosols during the a piled fluvial series into the the center of this new Petrified Tree Representative (Atchley et al., 2013 ; Loughney et al., 2011 ; Parker mais aussi al., 2005 ; Parker & ). PFV 297 and you may PFV 414 is actually broke up spatially by 20 yards and are consequently from the 200 yards on the southeast of PFV 231 (Shape 1a). Decorated Wilderness Sandstone step 3, which quickly underlies all around three localities, are stratigraphically
40–fifty yards above the base of the Petrified Tree Associate (Profile 1b; Parker & ), and you may represents a sheet sandstone placed by the recurrent circulate inside the a great high sinuosity river route (Johns, 1988 ). PFV 297 and you may PFV 414 occur some high throughout the succession than simply PFV 231 (Parker & ).