DOI: 10.5061/dryad.51248
title: Data from: A palaeoequatorial Ornithischian and new constraints on early dinosaur diversification

description: Current characterizations of early dinosaur evolution are incomplete:
 existing palaeobiological and phylogenetic scenarios are based on a fossil
 record dominated by saurischians and the implications of the early
 ornithischian record are often overlooked. Moreover, the timings of deep
 phylogenetic divergences within Dinosauria are poorly constrained owing to
 the absence of a rigorous chronostratigraphical framework for key Late
 Triassic–Early Jurassic localities. A new dinosaur from the earliest
 Jurassic of the Venezuelan Andes is the first basal ornithischian
 recovered from terrestrial deposits directly associated with a precise
 radioisotopic date and the first-named dinosaur from northern South
 America. It expands the early palaeogeographical range of Ornithischia to
 palaeoequatorial regions, an area sometimes thought to be devoid of early
 dinosaur taxa, and offers insights into early dinosaur growth rates, the
 evolution of sociality and the rapid tempo of the global dinosaur
 radiation following the end-Triassic mass extinction, helping to
 underscore the importance of the ornithischian record in broad-scale
 discussions of early dinosaur history.
description: Laquintasaurus
 TreefileTreefile with results of
 published analysesLaquinta
 analysis_TreefileLaquintasaura_TNT
 datasetOriginal TNT data for
 early ornithischian phylogenetic analysisFigure2AHigh resolution image of Figure 2(a). Osteohistological section of small tibia (MBLUZ P.5021), from a juvenile individual: (a) complete section in normal-polarized transmitted light and (b) close-up of cortex in cross-polarized light using lambda compensator. The entire compacta consists of parallel-fibred bone subdivided by two growth annuli (marked by arrowheads). The bone tissue is vascularized by simple primary canals and woven bone is absent.Figure2BHigh resolution version of Figure 2(b). Figure 2. Osteohistological section of small tibia (MBLUZ P.5021), from a juvenile individual: (a) complete section in normal-polarized transmitted light and (b) close-up of cortex in cross-polarized light using lambda compensator. The entire compacta consists of parallel-fibred bone subdivided by two growth annuli (marked by arrowheads). The bone tissue is vascularized by simple primary canals and woven bone is absent.Supplement_S6AHigh resolution image of Supplementary Figure 6(a). Overview images of thin-sections of smaller right tibia P.5021 (A, B) and partial larger tibia P.5020 (C) sampled. Image A is in normal transmitted, B and C in polarised light using lambda compensator.Supplement_S6BHigh resolution image of Supplementary Figure 6(b). Figure S6. Overview images of thin-sections of smaller right tibia P.5021 (A, B) and partial larger tibia P.5020 (C) sampled. Image A is in normal transmitted, B and C in polarised light using lambda compensator.Supplement_S6CHigh resolution version of Figure S6(c). Overview images of thin-sections of smaller right tibia P.5021 (A, B) and partial larger tibia P.5020 (C) sampled. Image A is in normal transmitted, B and C in polarised light using lambda compensator.Supplement_S7AHigh resolution version of Supplementary Figure 7(a). Figure S7. Thin-sections of smaller right tibia P.5021 (A–C, F), the indeterminate long bone P.5023 (D) and femur P.5023 (E). Image C is in normal transmitted, A, D and E in polarised, and B and F in polarised light using lambda compensator. A, B. Cortical bone showing parallel-fibred bone tissue subdivided by two annuli (marked by arrowheads). C. Higher magnification of the cortical bone. The bone tissue is vascularized by numerous primary vascular canals, which are oriented longitudinally or obliquely. D. Close-up view of the cortical parallel-fibred bone tissue with reticular vascularisation pattern. E. Close-up of cortex with laminar organisation of vascular spaces. F. Remnant of endosteal lamellar bone tissue (marked by arrowheads) surrounding in part the medullary cavity. PC, primary vascular canals; PFB, parallel-fibred bone.Supplement_S7BHigh resolution version of Supplementary Figure 7(b). Figure S7. Thin-sections of smaller right tibia P.5021 (A–C, F), the indeterminate long bone P.5023 (D) and femur P.5023 (E). Image C is in normal transmitted, A, D and E in polarised, and B and F in polarised light using lambda compensator. A, B. Cortical bone showing parallel-fibred bone tissue subdivided by two annuli (marked by arrowheads). C. Higher magnification of the cortical bone. The bone tissue is vascularized by numerous primary vascular canals, which are oriented longitudinally or obliquely. D. Close-up view of the cortical parallel-fibred bone tissue with reticular vascularisation pattern. E. Close-up of cortex with laminar organisation of vascular spaces. F. Remnant of endosteal lamellar bone tissue (marked by arrowheads) surrounding in part the medullary cavity. PC, primary vascular canals; PFB, parallel-fibred bone.Supplement_S7CHigh resolution version of Supplementary Figure 7(c). Figure S7. Thin-sections of smaller right tibia P.5021 (A–C, F), the indeterminate long bone P.5023 (D) and femur P.5023 (E). Image C is in normal transmitted, A, D and E in polarised, and B and F in polarised light using lambda compensator. A, B. Cortical bone showing parallel-fibred bone tissue subdivided by two annuli (marked by arrowheads). C. Higher magnification of the cortical bone. The bone tissue is vascularized by numerous primary vascular canals, which are oriented longitudinally or obliquely. D. Close-up view of the cortical parallel-fibred bone tissue with reticular vascularisation pattern. E. Close-up of cortex with laminar organisation of vascular spaces. F. Remnant of endosteal lamellar bone tissue (marked by arrowheads) surrounding in part the medullary cavity. PC, primary vascular canals; PFB, parallel-fibred bone.Supplement_S7DHigh resolution version of Supplementary Figure 7(d). Figure S7. Thin-sections of smaller right tibia P.5021 (A–C, F), the indeterminate long bone P.5023 (D) and femur P.5023 (E). Image C is in normal transmitted, A, D and E in polarised, and B and F in polarised light using lambda compensator. A, B. Cortical bone showing parallel-fibred bone tissue subdivided by two annuli (marked by arrowheads). C. Higher magnification of the cortical bone. The bone tissue is vascularized by numerous primary vascular canals, which are oriented longitudinally or obliquely. D. Close-up view of the cortical parallel-fibred bone tissue with reticular vascularisation pattern. E. Close-up of cortex with laminar organisation of vascular spaces. F. Remnant of endosteal lamellar bone tissue (marked by arrowheads) surrounding in part the medullary cavity. PC, primary vascular canals; PFB, parallel-fibred bone.Supplement_S7EHigh resolution version of Supplementary Figure 7(e). Figure S7. Thin-sections of smaller right tibia P.5021 (A–C, F), the indeterminate long bone P.5023 (D) and femur P.5023 (E). Image C is in normal transmitted, A, D and E in polarised, and B and F in polarised light using lambda compensator. A, B. Cortical bone showing parallel-fibred bone tissue subdivided by two annuli (marked by arrowheads). C. Higher magnification of the cortical bone. The bone tissue is vascularized by numerous primary vascular canals, which are oriented longitudinally or obliquely. D. Close-up view of the cortical parallel-fibred bone tissue with reticular vascularisation pattern. E. Close-up of cortex with laminar organisation of vascular spaces. F. Remnant of endosteal lamellar bone tissue (marked by arrowheads) surrounding in part the medullary cavity. PC, primary vascular canals; PFB, parallel-fibred bone.Supplement_S7FHigh resolution version of Supplementary Figure 7(f). Figure S7. Thin-sections of smaller right tibia P.5021 (A–C, F), the indeterminate long bone P.5023 (D) and femur P.5023 (E). Image C is in normal transmitted, A, D and E in polarised, and B and F in polarised light using lambda compensator. A, B. Cortical bone showing parallel-fibred bone tissue subdivided by two annuli (marked by arrowheads). C. Higher magnification of the cortical bone. The bone tissue is vascularized by numerous primary vascular canals, which are oriented longitudinally or obliquely. D. Close-up view of the cortical parallel-fibred bone tissue with reticular vascularisation pattern. E. Close-up of cortex with laminar organisation of vascular spaces. F. Remnant of endosteal lamellar bone tissue (marked by arrowheads) surrounding in part the medullary cavity. PC, primary vascular canals; PFB, parallel-fibred bone.Supplement_S8AHigh resolution version of Supplementary Figure 8(a). Figure S8. Overview images of thin-sectioned mid-shaft region of rib P.5029 (A) and partial left scapula P.5012 (B). Image A is in normal transmitted, B in polarised light using lambda compensator.Supplement_S8BHigh resolution version of Supplementary Figure 8(b). Figure S8. Overview images of thin-sectioned mid-shaft region of rib P.5029 (A) and partial left scapula P.5012 (B). Image A is in normal transmitted, B in polarised light using lambda compensator.Supplement_S9AHigh-resolution image of Supplementary Figure 9(a). Figure S9. Thin-sections of smaller partial left scapula P.5012 (A–C). Image A is in normal transmitted, B in polarised, and C in polarised light using lambda compensator. All three images show the same section of cortical bone in higher magnification. The bone surface is towards the bottom of the image. The primary parallel-fibred bone tissue is in various stages of remodelling by secondary osteons and erosion cavities. Two widely spaced incremental growth marks (i.e., lines of arrested growth, LAGs) are indicated with white arrowheads, whereas an external fundamental system consisting of about seven incremental LAGs is situated in close proximity to the external bone surface. Note the peculiar colouration of the bone cell lacunae in image C (blue colours), due to the infilling with green mineral phase (visible in A), i.e., chlorite. EC, erosion cavity; EFS, external fundamental system; PFB, parallel-fibred bone; SO, secondary osteon.Supplement_S9BHigh-resolution image of Supplementary Figure 9(b). Figure S9. Thin-sections of smaller partial left scapula P.5012 (A–C). Image A is in normal transmitted, B in polarised, and C in polarised light using lambda compensator. All three images show the same section of cortical bone in higher magnification. The bone surface is towards the bottom of the image. The primary parallel-fibred bone tissue is in various stages of remodelling by secondary osteons and erosion cavities. Two widely spaced incremental growth marks (i.e., lines of arrested growth, LAGs) are indicated with white arrowheads, whereas an external fundamental system consisting of about seven incremental LAGs is situated in close proximity to the external bone surface. Note the peculiar colouration of the bone cell lacunae in image C (blue colours), due to the infilling with green mineral phase (visible in A), i.e., chlorite. EC, erosion cavity; EFS, external fundamental system; PFB, parallel-fibred bone; SO, secondary osteon.Supplement_S9CHigh-resolution image of Supplementary Figure 9(c). Figure S9. Thin-sections of smaller partial left scapula P.5012 (A–C). Image A is in normal transmitted, B in polarised, and C in polarised light using lambda compensator. All three images show the same section of cortical bone in higher magnification. The bone surface is towards the bottom of the image. The primary parallel-fibred bone tissue is in various stages of remodelling by secondary osteons and erosion cavities. Two widely spaced incremental growth marks (i.e., lines of arrested growth, LAGs) are indicated with white arrowheads, whereas an external fundamental system consisting of about seven incremental LAGs is situated in close proximity to the external bone surface. Note the peculiar colouration of the bone cell lacunae in image C (blue colours), due to the infilling with green mineral phase (visible in A), i.e., chlorite. EC, erosion cavity; EFS, external fundamental system; PFB, parallel-fibred bone; SO, secondary osteon.