The Chinle Creation on PEFO has become well-old of the high-reliability U–Pb zircon many years and magnetostratigraphy, proving that the whole creation here was Norian-Rhaetian within the decades (Kent mais aussi al., 2018 , 2019 ; Ramezani ainsi que al., 2011 ; Rasmussen mais aussi al., 2020 ). Roentgen. callenderi takes place in this new uppermost Blue Mesa Representative courtesy middle Petrified Forest User on PEFO, that have a numerical age range away from
No specimens monitor any signs of scavenging behavior
218.5–210 Ma (middle-later Norian; Rasmussen mais aussi al., 2020 ). Discover certain suspicion throughout the period of the reduced region of your Sonsela User with regards to the many years model selected (Rasmussen et al., 2020 ) but this doesn’t change the age the first otherwise history events out of Roentgen. callenderi during the PEFO.
2.2 Taphonomy
Numerous parts of Roentgen. callenderi were amassed out-of PFV 297, anywhere between broken separated bones to partly articulated skeletons. , 2007 ). The brand new specimens was indeed all recovered blackcupid giriЕџ from a single opinions within the an effective greenish-grey mudstone (“blue internet” regarding Loughney mais aussi al., 2011 ) which is next to a channel facies of Painted Wasteland Sandstone step 3 (Parker ainsi que al., 2005 ), and that probably show levee dumps in the proximal portion of the floodplain (T. Demko, individual communications, ). Almost every other vertebrate localities on the Petrified Tree Representative occur contained in this comparable drab-coloured bedrooms that have been translated since the symbolizing badly drained paleosols inside given up route complete which were at the least seasonally drinking water-soaked (Loughney et al., 2011 ; Therrien & Fastovsky, 2000 ). Monodominant assemblages are not occur in wetland facies (age.grams., overbank wetland/limited pool) which have lowest transport and you may reworking potential (Eberth et al., 2007 ), and this refers to consistent with the interpretation of your depositional environment off “blue web sites” of Loughney ainsi que al. ( 2011 ). The presence of traditional equisetalean herbs (elizabeth.grams., PEFO 41412) regarding quarry together with aids that it translation. For the many of specimens away from PFV 297 and you may PFV 414, the inner areas of the limbs had been permineralized because of the calcite spar, and in some cases, the newest skeleton are also overgrown by a slimmer calcite spar coating. Many issue possess experienced limited synthetic deformation and you can brittle distortion because the evidenced by fracturing and you can displacement into the specimens of long bones. Otherwise skin bones preservation was exquisite, sustaining okay external information (age.g., muscle tissue markings) in many specimens, particularly in PEFO 34561.
The initial matter away from PFV 297 is receive in early 2004 and you will compiled mostly just like the surface “float” one eroded out of the fossiliferous vista, having one out of-situ articulated sample with a partial head (PEFO 33787). Counts regarding best ilia, proper femora, and you can leftover frontals conveyed this new preservation out-of no less than five someone (Parker ainsi que al., 2005 ). Then excavation regarding inside the-situ specimens contained of many isolated facets together with four related skeletons (PEFO 34269; PEFO 34561; PEFO 36875; PEFO 36876). PEFO 34561 signifies around 90% of an individual and will be offering all the description considering less than. PEFO 36875 and contains an entire and mainly articulated head as well while the a partially articulated postcranial bones. An enthusiastic articulated head (PEFO 38609) plus one bones was basically gathered into the 2015 (PEFO 42442/UWBM 116869) out-of PFV 414; PEFO 42442/UWBM 116869 preserves the spine line and carapace of trunk area into the limited articulation, as well as a complete, but hit bottom, skull. Such skeletons exists due to the fact seemingly remote levels of bones out-of solitary someone e bed linen flat of the an average of 1–dos yards. Along with her all the thing off PFV 297 and you may PFV 414 represents a minimum of a dozen some body based on femora counts. Mukherjee and you may Ray ( 2012 ) described a comparable taphonomic form to have a good rhynchosaur-dominated bonebed on the Upper Triassic Tiki Creation out-of Asia. Like with new Indian assemblage, it is probable at PFV 297 and PFV 414, toward fine-grained sediments and also in-situ equisitaleans, you to flaccid-structure decomposition on shallow water breadth and you may next weathering techniques disarticulated people regarding Roentgen. callenderi. Such skeletons was after exposed to limited dispersal of the low-energy fluvial representatives and eventually burial during the floodplain deposits (Mukherjee & Beam, 2012 ). The fresh new rareness regarding small issues particularly gastralia and you can chevrons inside if not almost complete specimens, therefore the exposure regarding remote head, girdle, and you will limb skeleton of the identical taxon, supports that it latter dispersal event (Mukherjee & Beam, 2012 ).