DOI: 10.5061/dryad.2z34tmpk8
title: Data from: An early-diverging procolophonid from the lowermost Triassic of South America and the origins of herbivory in Procolophonoidea

description: The Procolophonoidea was the only parareptile clade to survive the
 end-Permian mass extinction, experiencing an important adaptive radiation
 during the Triassic. The flourishing of procolophonoid lineages in highly
 stressful post-extinction environments may be, at least in part, a result
 of their early adaptations to herbivory, which would eventually become the
 commonest feeding strategy in later representatives of the group. Although
 procolophonoids are comparatively diverse in the South African
 Lystrosaurus Assemblage Zone, only the globally widespread taxon
 Procolophon trigoniceps was thus far reported in South American deposits
 of similar age. Here we present a new procolophonid genus and species for
 the Lower Triassic Sanga do Cabral Formation of Brazil. Oryporan insolitus
 gen. et sp. nov. combines typical adaptations for herbivory with primitive
 character states that are peculiar to early procolophonoids. Accordingly,
 our phylogenetic results place the new species as an early-diverging
 procolophonid, thus far the phylogenetically earliest to develop
 adaptations for herbivory. Character optimization shows that the bulbous
 labiolingually expanded molariforms of most procolophonids – interpreted
 as indicative of high-fibre herbivory – were co-opted from an
 insectivorous dentition. The new taxon also highlights the diversity of
 feeding habits displayed by Early Triassic procolophonoids, which was
 probably crucial for the survivorship of the clade in post-extinction
 disaster communities.
description: <i>X-ray microtomography analysis and
 3D-modelling</i><br> <br> In order to access relevant
 characters that were not exposed by mechanical preparation, like the
 palatal dentition and the marginal dentition in occlusal view, we
 conducted high-resolution X-ray computed tomography of UFSM 11443 using a
 SkyScan 1173 tomograph scanner at the Laboratório de Sedimentologia e
 Petrologia, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS).
 The scan was set with 130 kV of X-ray energy, 130 μA of current and 1100
 ms of exposure time. The procedure resulted in 1910 tomographic slices
 containing skull data of the specimen. Virtual preparation and
 segmentation of skull elements were performed using AVIZO.
 <i>Phylogenetic analyses</i> The
 phylogenetic relationships of UFSM 11443 were tested through a heuristic
 analysis using a modified version of the dataset of Cisneros (2008a).
 Besides the addition of UFSM 11443 as an independent operational taxonomic
 unit (OTU), the dataset also includes <i>Kitchingnathus
 untabeni</i>, <i>Phonodus dutoitorum </i>(see Cisneros
 2008b; Modesto <i>et al.</i> 2010; MacDougall &
 Modesto 2011), <i>Lasasaurus beltanae </i>(Falconnet
 <i>et al.</i> 2012) and <i>Mandaphon nadra
 </i>(Tsuji 2017). We have also included updated character scores for
 some of the OTUs, based on MacDougall & Modesto (2011) and
 MacDougall <i>et al</i>. (2013), as well as an additional
 character (character 10 from Modesto <i>et al.</i> 2001,
 following MacDougall & Modesto 2011). The resulting dataset is
 composed of 28 OTUs and 59 characters. Some characters were treated as
 additive, according to their original proposal by Cisneros (2008a).
  Heuristic searches were conducted using TNT (Tree analysis using New
 Technology) v.1.5 (Goloboff & Catalano 2016), using the tree
 bisection reconnection (TBR) algorithm of TNT (100 replications, 100 trees
 saved per replication, random seed).