Not surprisingly higher level traditional record, the newest dating from very early-diverging suchians are nevertheless incompletely realized (age

William Grams. Parker, Office from Money Administration, Petrified Forest Federal Playground, P. O. Package 2217, Petrified Tree, AZ 86028, U . s ..

Contribution: Conceptualization (equal), Specialized data (lead), Financial support purchase (lead), ?Study (lead), Strategy (lead), Creating – brand spanking new write (equal), Writing – opinion & modifying (equal)

William G. Parker, Section off Money Management, Petrified Forest National Park, P. O. Container 2217, Petrified Tree, AZ 86028, U . s ..

Contribution: Conceptualization (equal), Certified study (lead), Resource order (lead), ?Analysis (lead), Methods (lead), Writing – brand spanking new draft (equal), Creating – comment & modifying (equal)


After known only regarding dental care point and you will thought to portray an very early ornithischian dinosaur, the early-diverging pseudosuchian Revueltosaurus callenderi try explained away from a minimum of several skeletons off an excellent monodominant bonebed throughout the upper part of the Chinle Creation off Arizona. It material is sold with nearly the entire skeleton and contains a combo regarding plesiomorphic and you will derived character states that will clarify ingroup relationships inside Pseudosuchia. A good phylogenetic analysis recovers R. callenderi in the an effective clade that have Aetosauria and you may Acaenasuchus geoffreyi that is named Aetosauriformes. Key autapomorphies out of Roentgen. callenderi are a head which is more than brand new femur, a whole carapace of dermal armor together with paramedian and you will horizontal rows, including ventral osteoderms, and you will an end avoid sheathed in limbs. Histology of the femur and relevant osteoderms demonstrate that R. callenderi is slow-growing which individuals throughout the bonebed weren’t younger juveniles however, had not stopped expanding. A peek at other matter allotted to Revueltosaurus ends up the genus cannot be adequately identified based on the variety of product off the 3 tasked types and that simply R. callenderi shall be with confidence regarded Revueltosaurus.

step 1 Introduction

Late Triassic non-marine vertebrate assemblages had been an over-all selection of archosaurs you to originate and go extinct on Triassic Period (e.grams., non-dinosaurian avemetatarsalians, non-crocodylomorph pseudosuchians), crown-category archosaurs you to came from the brand new Triassic but varied afterwards inside the brand new Mesozoic Time (e.grams., crocodylomorphs, pterosaurs, and you may dinosaurs), or other plentiful non-archosaurian archosauromorphs present only when you look at the Triassic Months (e.g., tanystropheids, rhynchosaurs, allokotosaurians). The final 2 decades away from browse show that lots of this type of lineages general to the Triassic got unanticipated morphological and environmental specializations (elizabeth.g., Dzik, 2003 ; Ezcurra, 2016 ; Ezcurra mais aussi al., 2020 ; Flynn mais aussi al., 2010 ; Foth et al., 2016 ; Irmis, Nesbitt, mais aussi al., 2007 ; Nesbitt, 2003 ; Nesbitt, 2005a ; Nesbitt, 2007 ; Nesbitt & Butler, 2013 ; Nesbitt & Norell, 2006 ; Nesbitt mais aussi al., 2009 , 2010 , 2017 ; Nesbitt et al., 2014 ; Parker ainsi que al., 2005 ; Sengupta mais aussi al., 2017 ; Stocker ainsi que al., 2016 ; Sues, 2003 ). Of a lot non-archosaur archosauromorphs and you may top archosaurs had a package regarding profile says which were thought to be introduce only in almost any groups of dinosaurs. Particularly, the fresh poposauroid pseudosuchians Shuvosaurus inexpectatus and you will Effigia okeeffeae enjoys an upright bipedal posture with theropod dinosaur-eg skulls (Nesbitt, 2007 ; Nesbitt & Norell, 2006 ; Parker & Nesbitt, 2013 ), brand new dorsal part of the cranium is expanded toward a beneficial dome in Triopticus primus and you can pachycephalosaurian dinosaurs (Stocker ainsi que al., 2016 ), therefore the low-archosaur archosauromorph Azendohsaurus madagaskarensis, the newest suchian archosaur Revueltosaurus callenderi, as well as the low-dinosaurian dinosauriform Silesaurus opolensis the provides pearly whites that will be nearly identical away from those of early ornithischian dinosaurs (Dzik, 2003 ; Flynn mais aussi al., 2010 ; Irmis, Parker mais aussi al., 2007 ; Nesbitt ainsi que al., 2010 , 2015 ).

Many “dinosaur-like” Triassic reptiles fall into brand new clade Pseudosuchia; such crocodile-line archosaurs are among the most commonly retrieved low-aquatic tetrapods from the Late Triassic Epoch around the Pangea. g., Brusatte mais aussi al., 2010 ; Butler mais aussi al., 2014 ; Ezcurra ainsi que al., 2017 ; Gower & Wilkinson, 1996 ; Nesbitt, 2011 ; Nesbitt, Stocker, mais aussi al., 2018 ; von Baczko & Ezcurra, 2013 ). Renewed need for men and women early-diverging pseudosuchians, and additionally the brand new discoveries, features considerably improved all of our comprehension of the range, disparity, and phylogenetic dating (age.g., Butler mais aussi al., 2014 ; Butler mais aussi al., 2018 ; Desojo ainsi que al., 2013 ; Desojo et al., 2020 ; Ezcurra et al., 2017 ; Irmis ainsi que al., 2013 ; ; Nesbitt ainsi que al., 2014 ; Nesbitt, Brusatte, ainsi que al., 2013 ; Nesbitt, Desojo, & Irmis, 2013 ; Nesbitt, Stocker, et al., 2018 ; von Baczko ainsi que al., 2020 ; von Baczko & Ezcurra, 2013 ). Brand new breakthrough regarding early-diverging pseudosuchian taxa having a variety of plesiomorphic and apomorphic profile claims help describe a number of the into the-category matchmaking within Pseudosuchia, but at the same time comes with shown homoplasy in some reputation states (elizabeth.g., Ezcurra ainsi que al., 2017 ; b ; Nesbitt, 2011 ; Nesbitt et al., 2011 ; Nesbitt & Butler, 2013 ; Nesbitt & Norell, 2006 ; Parker mais aussi al., 2005 ).