The latest Chinle Development at PEFO is better-old by the large-precision You–Pb zircon years and you will magnetostratigraphy, proving the entire development in this area is Norian-Rhaetian in the years (Kent mais aussi al., 2018 , 2019 ; Ramezani et al., 2011 ; Rasmussen ainsi que al., 2020 ). Roentgen. callenderi takes place in the new uppermost Bluish Mesa Representative through middle Petrified Forest User from the PEFO, that have a mathematical age groups out of
Zero specimens display screen one signs and symptoms of scavenging behavior
218.5–210 Ma (middle-later Norian; Rasmussen mais aussi al., 2020 ). There is some uncertainty throughout the age the low region of the Sonsela Representative depending on the many years model chosen (Rasmussen mais aussi al., 2020 ) however, this doesn’t impact the age of the first or last occurrences off R. callenderi in the PEFO.
Hundreds of elements of Roentgen. callenderi have been obtained away from PFV 297, between busted isolated skeleton in order to partly articulated skeletons. , 2007 ). The new specimens was all of the retrieved from opinions when you look at the an effective greenish-gray mudstone (“bluish websites” off Loughney ainsi que al., 2011 ) which is next to a channel facies of Decorated Wasteland Sandstone step three (Parker ainsi que al., 2005 ), and this probably show levee deposits regarding proximal part of the floodplain (T. Demko, personal communication, ). Almost every other vertebrate localities in the Petrified Tree Affiliate exist contained in this equivalent drab-coloured bedrooms which have been interpreted since the representing badly drained paleosols during the given up station complete that have been no less than seasonally liquids-over loaded (Loughney mais aussi al., 2011 ; Therrien & Fastovsky, 2000 ). Monodominant assemblages are not occur in wetland facies (elizabeth.g., overbank wetland/marginal pool) having low transport and you may reworking prospective (Eberth et al., 2007 ), and this is similar to the interpretation of your depositional environment off “bluish sites” from Loughney et al. ( 2011 ). The existence of fossil equisetalean vegetation (e.g., PEFO 41412) throughout the quarry and supports so it interpretation. During the several of specimens off PFV 297 and PFV 414, the internal areas of bones was permineralized because of the calcite spar, and in some cases, this new bones also are overgrown because of the a finer calcite spar layer. Of several elements has actually undergone slight plastic material distortion and you may brittle distortion as the evidenced by the fracturing and displacement in specimens out of a lot of time bones. Otherwise surface bone maintenance is actually superb, retaining great additional info (age.g., muscle markings) a number of specimens, particularly in PEFO 34561.
The first matter off PFV 297 is located in early 2004 and you may accumulated generally due to the fact epidermis “float” one eroded from the fossiliferous panorama, having one out of-situ articulated sample which have a limited skull (PEFO 33787). Counts off best ilia, right femora, and you can kept frontals conveyed the brand new maintenance out of a minimum of five people (Parker mais aussi al., 2005 ). Next excavation off during the-situ specimens contained of many isolated points in addition to four associated skeletons (PEFO 34269; PEFO 34561; PEFO 36875; PEFO 36876). PEFO 34561 stands for doing ninety% of people and provides all of the malfunction offered lower than. PEFO 36875 and has now a whole and you can mainly articulated head as well once the a partly articulated postcranial bones. A keen articulated head (PEFO 38609) and another bones was built-up inside 2015 (PEFO 42442/UWBM 116869) from PFV 414; PEFO 42442/UWBM 116869 saves the brand new spine line and you may carapace of your trunk area region in the partial articulation, in addition to a whole, however, flattened, head. These skeletons exists just like the seemingly remote density out-of bones out of unmarried someone e bedding airplanes because of the typically step one–dos yards. With her all of the topic off PFV 297 and PFV 414 is short for at least several anybody centered on femora matters. Mukherjee and you may Beam ( 2012 ) discussed an equivalent taphonomic function having an excellent rhynchosaur-reigned over bonebed from the Higher Triassic Tiki Formation away from India. Like with the latest Indian assemblage, it is likely from the PFV 297 and you may PFV 414, into the great-grained sediments and in-situ equisitaleans, one to flaccid-cells decomposition in the shallow water depth and then weathering techniques disarticulated the folks out of Roentgen. callenderi. This type of skeletons was in fact later on exposed to limited dispersal by low energy fluvial representatives and in the end burial from inside the floodplain deposits (Mukherjee & Ray, 2012 ). The rareness away from brief factors particularly gastralia and chevrons inside if you don’t almost over specimens, together with presence from separated skull, girdle, and you can limb bones of the same taxon, aids it second dispersal feel (Mukherjee & Ray, 2012 ).