Scott Hartman
University of Wisconsin-Madison, Department of Integrative Biology, Department Member
SynopsisTyrannosaurid dinosaurs had large preserved leg muscle attachments and low rotational inertia relative to their body mass, indicating that they could turn more quickly than other large theropods.MethodsTo compare turning... more
SynopsisTyrannosaurid dinosaurs had large preserved leg muscle attachments and low rotational inertia relative to their body mass, indicating that they could turn more quickly than other large theropods.MethodsTo compare turning capability in theropods, we regressed agility estimates against body mass, incorporating superellipse-based modeled mass, centers of mass, and rotational inertia (mass moment of inertia). Muscle force relative to body mass is a direct correlate of agility in humans, and torque gives potential angular acceleration. Agility scores therefore include rotational inertia values divided by proxies for (1) muscle force (ilium area and estimates of m. caudofemoralis longus cross-section), and (2) musculoskeletal torque. Phylogenetic ANCOVA (phylANCOVA) allow assessment of differences in agility between tyrannosaurids and non-tyrannosaurid theropods (accounting for both ontogeny and phylogeny). We applied conditional error probabilitiesa(p) to stringently test the nul...
Research Interests: Mathematics, Biomechanics, Biology, Medicine, Theropoda, and 5 morePredation, Agility, Moment of Inertia, Torque, and Inertia
The biogeography of terrestrial amniotes is controlled by historical contingency interacting with paleoclimate, morphology and physiological constraints to dispersal. Thermal tolerance is the intersection between organismal requirements... more
The biogeography of terrestrial amniotes is controlled by historical contingency interacting with paleoclimate, morphology and physiological constraints to dispersal. Thermal tolerance is the intersection between organismal requirements and climate conditions which constrains modern organisms to specific locations and was likely a major control on ancient tetrapods. Here, we test the extent of controls exerted by thermal tolerance on the biogeography of 13 Late Triassic tetrapods using a mechanistic modeling program, Niche Mapper. This program accounts for heat and mass transfer into and out of organisms within microclimates. We model our 13 tetrapods in four different climates (cool and warm at low and high latitudes) using environmental conditions that are set using geochemical proxy-based general circulation models. Organismal conditions for the taxa are from proxy-based physiological values and phylogenetic bracketing. We find that thermal tolerances are a sufficient predictor f...
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Figure 12. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Hindlimb elements. A, Distal end of left femur and proximal end of left tibia. B, Right tarsus in cranial view. C, Left tarsus in craniomedial view. ap,... more
Figure 12. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Hindlimb elements. A, Distal end of left femur and proximal end of left tibia. B, Right tarsus in cranial view. C, Left tarsus in craniomedial view. ap, ascending process of astragalus; as, astragalus; ca, calcaneus; cn, cnemial crest of left tibia; fe, distal end of left femur; fi, fibula.
Figure 10. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Wing bones. A, X-Ray photograph showing right scapula, humerus, ulna, and radius. B, Cranial aspect of proximal end of right humerus. C, Detail of right... more
Figure 10. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Wing bones. A, X-Ray photograph showing right scapula, humerus, ulna, and radius. B, Cranial aspect of proximal end of right humerus. C, Detail of right wrist. D, Left manus. E, Right manus. hu, humerus; pxII, proximal end of second metacarpal; ra, radius; sc, scapula; slc, semilunate carpal; ul, ulna. The fingers are numbered.
Figure 7. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). X-Ray photograph showing cervical vertebrae and part of right manus. cv, cervical vertebrae.
Niche Mapper output files plotted in R and ggplot2. Only contains burrowing taxa, with burrowing turned on.
Raw Niche Mapper output plots from R and ggplot2.
Full resolution Niche Mapper output files plotted in R and ggplot2. Only contains burrowing taxa, with burrowing turned on.
3d scan and color map of the entire body block of WDC DML-001.
Figure 11. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Pelvic girdle (A, B) and ischium (C) of the London specimen. A, Elements as preserved. B, Ultraviolet-induced fluorescence photograph. C, After El{anowski... more
Figure 11. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Pelvic girdle (A, B) and ischium (C) of the London specimen. A, Elements as preserved. B, Ultraviolet-induced fluorescence photograph. C, After El{anowski (2002), not to scale. dd, dorsodistal process; ip, intermediate process; isc, ischium; pu, pubis; vd, ventrodistal process. The arrows indicate the cranial and caudal ends of the ilium.
Figure 9. Elements of the pectoral girdle of Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG- 100). A, Furcula. B, Right coracoid. C, Left coracoid, scapula, and humerus. bct, biceps tubercle; co, coracoid; fns, foramen... more
Figure 9. Elements of the pectoral girdle of Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG- 100). A, Furcula. B, Right coracoid. C, Left coracoid, scapula, and humerus. bct, biceps tubercle; co, coracoid; fns, foramen nervi supracoracoidei; gl, glenoid process of coracoid; hu, humerus; pla, lateral process of coracoid; sc, scapula.
Figure 8. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Vertebral column. A, Dorsal vertebrae in ventrolateral view. B, Ultraviolet-induced fluorescence photograph of dorsal vertebrae. C, Sacrum in ventral view.... more
Figure 8. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Vertebral column. A, Dorsal vertebrae in ventrolateral view. B, Ultraviolet-induced fluorescence photograph of dorsal vertebrae. C, Sacrum in ventral view. D, Proximal section of caudal vertebrae in ventrolateral view. E, Distal section of caudal vertebrae in lateral and ventral view. ili, ilium; isc, ischium; pu, pubis. The dorsal (d), sacral (s), and caudal (c) vertebrae are numbered. The arrows indicate the cranial and caudal ends of the ilium.
Figure 13. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Feet. A, Left foot. B, X-Ray photograph of left foot. C, D, Distal end of right foot in dorsal (C) and dorsomedial (D) view. E, Distal end of left foot.... more
Figure 13. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Feet. A, Left foot. B, X-Ray photograph of left foot. C, D, Distal end of right foot in dorsal (C) and dorsomedial (D) view. E, Distal end of left foot. fe, feather impressions; tr, proximodorsally expanded articular trochlea of first phalanx of second toe. The pedal digits are numbered.
Figure 6. A, Reconstruction of the palate of Archaeopteryx siemensii Dames, 1897, according to information on the shape of the palatine and the position of the ectopterygoid from the new specimen. B, Reconstruction of El{anowski (2001a).... more
Figure 6. A, Reconstruction of the palate of Archaeopteryx siemensii Dames, 1897, according to information on the shape of the palatine and the position of the ectopterygoid from the new specimen. B, Reconstruction of El{anowski (2001a). In A, the lateral margin of the broken palate of the Munich specimen is indicated by a broken line. ec, ectopterygoid; pg, pterygoid; pqw, prequadrate wing; pt, palatine; v, vomer.
Figure 5. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Skull. A, Detail of antorbital fenestra with palatine bone. B, Detail of right orbital region with pterygoid and ectopterygoid. C, Detail of dentition.... more
Figure 5. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Skull. A, Detail of antorbital fenestra with palatine bone. B, Detail of right orbital region with pterygoid and ectopterygoid. C, Detail of dentition. cdp, caudodorsal process of jugal; ch, choanal process of palatine; ec, ectopterygoid; hy, hyoid; j, jugal; jp, jugal process of palatine; md, mandible; mf, maxillary fenestra; mx, maxilla; na, nasal; pf, promaxillary fenestra; pl, palatine; pm, premaxilla; pt, pterygoid; q, quadrate;?, unidentified bone. The maxillary (m) and premaxillary (pm) teeth are numbered.
Figure 2. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Ultraviolet-induced fluorescence photograph showing the preserved bone substance.
Figure 3. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Interpretative drawing of the skeleton. The hatched elements were restored by the preparator. The primaries are numbered; their approximate course and area... more
Figure 3. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100). Interpretative drawing of the skeleton. The hatched elements were restored by the preparator. The primaries are numbered; their approximate course and area of insertion are indicated by the dotted line, which is orientated by the preserved impressions of parts of the rachises. cor, coracoid; fem, femur; fur, furcula; hum, humerus; sca, scapula. Left and right elements are indicated by (l) and (r), respectively.
Figure 1. Archaeopteryx siemensii Dames, 1897, Thermopolis specimen (WDC-CSG-100).
Raw input file in csv format for microclimates used in dissertation research
Raw Niche Mapper output plots from R and ggplot2.
Output text files of all simulated runs from Niche Mapper simulation for Late Triassic and ETE.
Raw input file in csv format for eight Niche Mapper microclimate models
Niche Mapper biophysical model inputs for 13 species in 8 different environments.
The last two decades have seen a remarkable increase in the known diversity of basal avialans and their paravian relatives. The lack of resolution in the relationships of these groups combined with attributing the behavior of specialized... more
The last two decades have seen a remarkable increase in the known diversity of basal avialans and their paravian relatives. The lack of resolution in the relationships of these groups combined with attributing the behavior of specialized taxa to the base of Paraves has clouded interpretations of the origin of avialan flight. Here, we describe Hesperornithoides miessleri gen. et sp. nov., a new paravian theropod from the Morrison Formation (Late Jurassic) of Wyoming, USA, represented by a single adult or subadult specimen comprising a partial, well-preserved skull and postcranial skeleton. Limb proportions firmly establish Hesperornithoides as occupying a terrestrial, non-volant lifestyle. Our phylogenetic analysis emphasizes extensive taxonomic sampling and robust character construction, recovering the new taxon most parsimoniously as a troodontid close to Daliansaurus, Xixiasaurus, and Sinusonasus. Multiple alternative paravian topologies have similar degrees of support, but propos...
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We describe the tenth skeletal specimen of the Upper Jurassic Archaeopterygidae. The almost complete and well-preserved skeleton is assigned to Archaeopteryx siemensii Dames, 1897 and provides significant new information on the osteology... more
We describe the tenth skeletal specimen of the Upper Jurassic Archaeopterygidae. The almost complete and well-preserved skeleton is assigned to Archaeopteryx siemensii Dames, 1897 and provides significant new information on the osteology of the Archaeopterygidae. As is ...
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12 A New Chasmosaurine Ceratopsid from the Judith River Formation, Montana MICHAEL J. RYAN, ANTHONY P. RUSSELL, AND SCOTT HARTMAN a new chasmosaurine ceratopsid, Medusaceratops lokii, is described based on material collected from a ...
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Abstract—Duckbill dinosaur chin skin (DCS) has been discovered in direct association with the underside of a dinosaurjaw from the" This Side ofHell Wyoming"(TSOH) quarry. The quarry is located on United States Depart ment ofthe... more
Abstract—Duckbill dinosaur chin skin (DCS) has been discovered in direct association with the underside of a dinosaurjaw from the" This Side ofHell Wyoming"(TSOH) quarry. The quarry is located on United States Depart ment ofthe Interior Bureau ofLand Management administered lands in northwestern Wyoming. The dinosaur re mains are preserved within regionally laterally continuous, very fine-grained sheet sandstone beds ofthe Upper Cre taceous (Maastrichtian) Lance Formation. Well-preserved dinosaur elements that were at ...
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We employed the widely-tested biophysiological modeling software, Niche Mapper™ to investigate the metabolic function of Late Triassic dinosaurs Plateosaurus and Coelophysis during global greenhouse conditions. We tested them under a... more
We employed the widely-tested biophysiological modeling software, Niche Mapper™ to investigate the metabolic function of Late Triassic dinosaurs Plateosaurus and Coelophysis during global greenhouse conditions. We tested them under a variety of assumptions about resting metabolic rate, evaluated within six microclimate models that bound paleoenvironmental conditions at 12° N paleolatitude, as determined by sedimentological and isotopic proxies for climate within the Chinle Formation of the southwestern United States. Sensitivity testing of metabolic variables and simulated “metabolic chamber” analyses support elevated “ratite-like” metabolic rates and intermediate “monotreme-like” core temperature ranges in these species of early saurischian dinosaur. Our results suggest small theropods may have needed partial to full epidermal insulation in temperate environments, while fully grown prosauropods would have likely been heat stressed in open, hot environments and should have been rest...
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Body shape is a fundamental expression of organismal biology, but its quantitative reconstruction in fossil vertebrates is rare. Due to the absence of fossilized soft tissue evidence, the functional consequences of basal paravian body... more
Body shape is a fundamental expression of organismal biology, but its quantitative reconstruction in fossil vertebrates is rare. Due to the absence of fossilized soft tissue evidence, the functional consequences of basal paravian body shape and its implications for the origins of avians and flight are not yet fully understood. Here we reconstruct the quantitative body outline of a fossil paravian Anchiornis based on high-definition images of soft tissues revealed by laser-stimulated fluorescence. This body outline confirms patagia-bearing arms, drumstick-shaped legs and a slender tail, features that were probably widespread among paravians. Finely preserved details also reveal similarities in propatagial and footpad form between basal paravians and modern birds, extending their record to the Late Jurassic. The body outline and soft tissue details suggest significant functional decoupling between the legs and tail in at least some basal paravians. The number of seemingly modern propa...
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The last two decades have seen a remarkable increase in the known diversity of basal avialans and their paravian relatives. The lack of resolution in the relationships of these groups combined with attributing the behavior of specialized... more
The last two decades have seen a remarkable increase in the known diversity of basal avialans and their paravian relatives. The lack of resolution in the relationships of these groups combined with attributing the behavior of specialized taxa to the base of Paraves has clouded interpretations of the origin of avialan flight. Here, we describe Hesperornithoides miessleri gen. et sp. nov., a new paravian theropod from the Morrison Formation (Late Jurassic) of Wyoming, USA, represented by a single adult or subadult specimen comprising a partial, well-preserved skull and postcranial skeleton. Limb proportions firmly establish Hesperornithoides as occupying a terrestrial, non-volant lifestyle. Our phylogenetic analysis emphasizes extensive taxonomic sampling and robust character construction, recovering the new taxon most parsimoniously as a troodontid close to Daliansaurus, Xixiasaurus, and Sinusonasus. Multiple alternative paravian topologies have similar degrees of support, but proposals of basal paravian archaeopterygids, avialan microraptorians, and Rahonavis being closer to Pygostylia than archaeopterygids or unenlagiines are strongly rejected. All parsimonious results support the hypothesis that each early paravian clade was plesiomorphically flightless, raising the possibility that avian flight originated as late as the Late Jurassic or Early Cretaceous.