Iguanomorpha (stem + crown Iguania) is a diverse squamate clade with members that predominate many modern American lizard ecosystems. However, the temporal and palaeobiogeographic origins of its constituent crown clades (e.g. Pleurodonta (basilisks, iguanas, and their relatives)) are poorly constrained, mainly due to a meagre Mesozoic-age fossil record. Here, we report on two nearly complete skeletons from the Late Cretaceous (Campanian) of North America that represent a new and relatively large-bodied and possibly herbivorous iguanomorph that inhabited a semi-arid environment. The new taxon exhibits a mosaic of anatomical features traditionally used in diagnosing Iguania and non-iguanian squamates (i.e. Scleroglossa; e.g. parietal foramen at the frontoparietal suture, astragalocalcaneal notch in the tibia, respectively). Our cladistic analysis of Squamata revealed a phylogenetic link between Campanian-age North American and East Asian stem iguanomorphs (i.e. the new taxon + Temujiniidae). These results and our evaluation of the squamate fossil record suggest that crown pleurodontans were restricted to the low-latitude Neotropics prior to their early Palaeogene first appearances in the mid-latitudes of North America.
ESM Video 1_MOR 7042 roll
This is a video of a three-dimensional model of the skull of Magnuviator ovimonsensis (MOR 7042).
ESM Video 2_MOR 7042 yaw
This is a video of a three-dimensional model of the skull of Magnuviator ovimonsensis (MOR 7042).
ESM Video 3_MOR 7042 pitch
This is a video of a three-dimensional model of the skull of Magnuviator ovimonsensis (MOR 7042).
ESM Video 4_MOR 7042 braincase roll
This is a video of a three-dimensional model of the braincase of Magnuviator ovimonsensis (MOR 7042).
ESM Video 5_MOR 7042 braincase yaw
This is a video of a three-dimensional model of the braincase of Magnuviator ovimonsensis (MOR 7042).
ESM Video 6_MOR 7042 braincase pitch
This is a video of a three-dimensional model of the braincase of Magnuviator ovimonsensis (MOR 7042).
ESM Video 7_MOR 7042 snout roll
This is a video of a three-dimensional model of the snout of Magnuviator ovimonsensis (MOR 7042).
ESM Video 8_MOR 7042 snout yaw
This is a video of a three-dimensional model of the snout of Magnuviator ovimonsensis (MOR 7042).
ESM Video 9_MOR 7042 snout pitch
This is a video of a three-dimensional model of the snout of Magnuviator ovimonsensis (MOR 7042).
DeMar et al._ESM file S1
This file contains supplementary text and 14 supplementary figures. The supplementary text provides (i) supplementary morphological descriptions; (ii) methodology on estimating squamate body-sizes; (iii) interpretations of the palaeoenvironmental setting of Magnuviator ovimonsensis and other relevant fossil iguanomorphs; (iv) new systematic interpretations of Late Cretaceous lizards previously assigned to Pleurodonta; (v) cladistic analysis methodologies and results; (vi) character scorings of Magnuviator ovimonsensis and Pariguana lancensis; (vii) information regarding CT and µCT scans; and (viii) a complete strict consensus tree and apomorphy list derived from our morphology-based cladistic analysis. The supplementary figures show additional specimen images, cladograms, and comparative body-size estimates of fossil and extant lizards. The text provides background information for interpretations made in the manuscript.
DeMar et al_ESM file S1.pdf
DeMar_et_al._ESM_file_S2
This file contains two tables: Table 1 includes skull, snout-vent length, and total body length measurements of fossil lizards. Table 2 provides a range of snout-vent lengths for extant adult iguanians.