The fresh buildup away from several people of mostly you to taxon categorizes this new locality because a monodominant bonebed (Eberth ainsi que al

The newest Chinle Development from the PEFO has started to become really-dated because of the high-reliability You–Pb zircon decades and you may magnetostratigraphy, appearing the entire development in this area is actually Norian-Rhaetian into the decades (Kent et al., 2018 , 2019 ; Ramezani ainsi que al., 2011 ; Rasmussen mais aussi al., 2020 ). R. callenderi happens in the latest uppermost Blue Mesa Associate as a result of middle Petrified Tree Representative during the PEFO, which have a mathematical age range off

Zero specimens screen people signs and symptoms of scavenging conclusion

218.5–210 Ma (middle-late Norian; Rasmussen ainsi que al., 2020 ). There was certain uncertainty in the ages of the low area of your own Sonsela User according to decades model chose (Rasmussen et al., 2020 ) however, this won’t change the age the initial or last incidents regarding Roentgen. callenderi within PEFO.

dos.dos Taphonomy

Countless elements of Roentgen. callenderi were built-up out-of PFV 297, ranging from damaged separated skeleton to partially articulated skeletons. , 2007 ). This new specimens was basically the recovered from a single horizon when you look at the an excellent greenish-gray mudstone (“bluish internet sites” out-of Loughney et al., 2011 ) that’s adjacent to a funnel facies of your own Painted Wasteland Sandstone step three (Parker mais aussi al., 2005 ), which probably portray levee dumps regarding proximal part of the floodplain (T. Demko, personal communication, ). Most other vertebrate localities on Petrified Tree Affiliate can be found contained in this equivalent drab-coloured bedrooms which have been interpreted once the representing defectively drained paleosols when you look at the abandoned channel complete that have been no less than seasonally water-saturated (Loughney mais aussi al., 2011 ; Therrien & Fastovsky, 2000 ). Monodominant assemblages commonly take place in wetland facies (elizabeth.g., overbank wetland/marginal pond) that have lower transport and you can reworking possible (Eberth ainsi que al., 2007 ), and this is consistent with the interpretation of the depositional ecosystem out-of “bluish sites” of Loughney mais aussi al. ( 2011 ). The existence of fossil equisetalean plant life (e.g., PEFO 41412) regarding the quarry and additionally supports so it translation. During the nearly all specimens regarding PFV 297 and you will PFV 414, the interior areas of bones were permineralized of the calcite spar, and in many cases, brand new skeleton are overgrown by a slimmer calcite spar level. Of numerous facets enjoys gone through moderate plastic deformation and you may weak distortion as the evidenced by fracturing and you will displacement for the specimens off enough time bones. Or even body bone preservation are exquisite, preserving great exterior information (elizabeth.g., muscles scars) in lot of specimens, especially in PEFO 34561.

The initial issue out-of PFV 297 was discover at the beginning of 2004 and you will amassed primarily as facial skin “float” you to definitely eroded out from the fossiliferous panorama, with one in-situ articulated specimen which have a partial skull (PEFO 33787). Matters away from right ilia, proper femora, and you may leftover frontals conveyed the brand new preservation out-of no less than five people (Parker mais aussi al., 2005 ). Further excavation out of into the-situ specimens contains of numerous remote factors plus four related skeletons (PEFO 34269; PEFO 34561; PEFO 36875; PEFO 36876). PEFO 34561 stands for as much as 90% of an individual and will be offering all the description provided lower than. PEFO 36875 and contains a whole and you can primarily articulated skull too just like the a partially articulated postcranial skeleton. An enthusiastic articulated head (PEFO 38609) and another skeleton was in fact collected in 2015 (PEFO 42442/UWBM 116869) of PFV 414; PEFO 42442/UWBM 116869 preserves this new spinal line and you can carapace of the trunk area area for the partial articulation, also an entire, but hit bottom, head. This type of skeletons exist as the apparently remote levels of skeleton away from unmarried individuals age bed linen benaughty buluЕџma airplane by typically step one–dos meters. Along with her the thing regarding PFV 297 and you can PFV 414 represents at least 12 some one predicated on femora matters. Mukherjee and you will Ray ( 2012 ) discussed a comparable taphonomic form for good rhynchosaur-ruled bonebed about Higher Triassic Tiki Creation away from Asia. Just as in the latest Indian assemblage, it’s possible during the PFV 297 and PFV 414, with the okay-grained sediments plus-situ equisitaleans, one to softer-muscle decomposition at shallow water depth and you may subsequent weathering procedure disarticulated people away from Roentgen. callenderi. Such skeletons was indeed afterwards exposed to limited dispersal because of the low-energy fluvial representatives and finally burial inside floodplain deposits (Mukherjee & Ray, 2012 ). The latest rareness off brief points such as for example gastralia and chevrons inside or even nearly complete specimens, together with visibility out of remote head, girdle, and limb bones of the same taxon, supporting that it latter dispersal experiences (Mukherjee & Ray, 2012 ).