The fresh new Chinle Development from the PEFO is actually well-old because of the highest-accuracy You–Pb zircon years and you will magnetostratigraphy, exhibiting that the whole development in this field try Norian-Rhaetian in the many years (Kent mais aussi al., 2018 , 2019 ; Ramezani et al., 2011 ; Rasmussen mais aussi al., 2020 ). Roentgen. callenderi takes place in the fresh new highest Blue Mesa Affiliate because of middle Petrified Forest Affiliate from the PEFO, with a numerical age groups regarding
Zero specimens screen any signs of scavenging decisions
218.5–210 Ma (middle-later Norian; Rasmussen et al., 2020 ). There can be particular suspicion about ages of the low part of your own Sonsela Affiliate depending on the many years model chosen (Rasmussen mais aussi al., 2020 ) but this won’t change the chronilogical age of the first otherwise past situations off Roentgen. callenderi within PEFO.
Numerous components of Roentgen. callenderi were built-up away from PFV 297, between broken remote bones to help you partly articulated skeletons. , 2007 ). Brand new specimens was basically the retrieved from vista for the an effective greenish-grey mudstone (“bluish web sites” off Loughney et al., 2011 ) that’s adjacent to a funnel facies of your Coated Wasteland Sandstone step 3 (Parker ainsi que al., 2005 ), and therefore probably depict levee deposits throughout the proximal portion of the floodplain (T. Demko, individual communication, ). Other vertebrate localities regarding Petrified Forest Associate are present contained in this equivalent drab-colored bedrooms which have been interpreted since the representing badly drained paleosols for the given up channel complete that were no less than seasonally water-saturated (Loughney mais aussi al., 2011 ; Therrien & Fastovsky, 2000 ). Monodominant assemblages aren’t occur in wetland facies (elizabeth.g., overbank wetland/limited pond) with reasonable transport and you may reworking prospective (Eberth mais aussi al., 2007 ), referring to consistent with the interpretation of the depositional ecosystem from “bluish web sites” out of Loughney ainsi que al. ( 2011 ). The existence of fossil equisetalean vegetation (e.grams., PEFO 41412) regarding quarry including supporting which translation. During the many of specimens out-of PFV 297 and you will PFV 414, the interior areas of your bones was basically permineralized from the calcite spar, and in some cases, this new bones are also overgrown by a eharmony giriЕџ thin calcite spar coating. Of many facets provides been through slight plastic material distortion and you may brittle distortion as confirmed by the fracturing and you can displacement inside specimens out-of long bones. Otherwise surface bones preservation are exquisite, sustaining great exterior information (age.grams., muscles scars) in lot of specimens, particularly in PEFO 34561.
The initial situation of PFV 297 try located at the beginning of 2004 and you can amassed primarily due to the fact body “float” one eroded out from the fossiliferous vista, that have one out of-situ articulated sample with a limited head (PEFO 33787). Counts out of right ilia, right femora, and you will remaining frontals conveyed the fresh new maintenance off no less than five someone (Parker et al., 2005 ). After that excavation off during the-situ specimens consisted of of many remote elements together with four related skeletons (PEFO 34269; PEFO 34561; PEFO 36875; PEFO 36876). PEFO 34561 represents around 90% of people and offers all the dysfunction given less than. PEFO 36875 and has an entire and you will mostly articulated skull too while the a partially articulated postcranial bones. An articulated head (PEFO 38609) and something skeleton was basically compiled into the 2015 (PEFO 42442/UWBM 116869) away from PFV 414; PEFO 42442/UWBM 116869 saves new spine column and you will carapace of trunk region during the limited articulation, along with an entire, however, flattened, skull. Such skeletons occur as the apparently isolated concentrations out of skeleton regarding unmarried people elizabeth bedding planes from the an average of 1–2 yards. Along with her every question of PFV 297 and you may PFV 414 represents no less than twelve some body according to femora matters. Mukherjee and Beam ( 2012 ) described the same taphonomic function to own good rhynchosaur-dominated bonebed regarding Upper Triassic Tiki Formation regarding Asia. As with the new Indian assemblage, it’s probable in the PFV 297 and PFV 414, towards the okay-grained sediments plus in-situ equisitaleans, one to soft-tissue decomposition at shallow water breadth and you may next weathering techniques disarticulated the people regarding Roentgen. callenderi. This type of skeletons was indeed later on confronted with partial dispersal of the low energy fluvial agencies and ultimately burial during the floodplain places (Mukherjee & Beam, 2012 ). New rarity of brief factors for example gastralia and you can chevrons inside or even almost over specimens, and also the presence off separated skull, girdle, and you may limb bones of the identical taxon, supporting that it second dispersal enjoy (Mukherjee & Beam, 2012 ).