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Ornithodira Crurotarsi Crown-clade Archosauria Basal archosaurs - PowerPoint PPT Presentation

Feb 19, 2024 •526 likes •920 views

Pterosauria Dinosauria Crocodylomorpha Rauisuchia Ornithosuchidae Ornithodira Crurotarsi Crown-clade Archosauria Basal archosaurs Archosauria Tanystropheus Prolacertiform Basal archosaur? Maybe... or it split off before archosauria

  1. Pterosauria Dinosauria Crocodylomorpha “Rauisuchia” Ornithosuchidae Ornithodira Crurotarsi Crown-clade Archosauria Basal archosaurs Archosauria

  2. Tanystropheus Prolacertiform Basal archosaur? Maybe... or it split off before archosauria prolacertiform? Archosauria Archosauromorpha

  3. Archosauria: synapomorphies Antorbital fenestra (in front of eye) Teeth with serrated margins Mandibular fenestra Proterosuchus Basal Archosaur

  5. Faculatative biped vs. Obligate biped Euparkeria (Facultative biped) Derived, Basal Archosaur Bony dermal plates down back

  6. Stances: sprawling <=> semi-erect <=> erect aquatic <=> terrestrial

  9. Locomotion (Pelvis) Rauisuchians -Pillar-Erect Posture Buttress-Erect Ornithodirans Mammals

  10. Locomotion: Pelvic/Hind leg conditions: Buttress-Erect Pillar-Erect Crocodylomorpha “Rauisuchia” Ornithosuchidae Ornithodira Crurotarsi Buttress-Erect Crown-clade Archosauria Basal archosaurs Archosauria

  11. Barrel-like articulation Constrained ‘twisting’ motion to the plane parallel with its body Digitigrade vs. Plantigrade

  12. PM: Primitive Metatarsal CN: Crocodyle Normal Hinge Crocodylomorphs/Rauisuchians calcaneum astragalus CR: Crocodyle Reversed Ornithosuchids AM: Advanced Mesotarsal Rotation Rotation Pterosaurs, Dinosaurs Hinge Proterosuchus

  13. The importance of a twisting ankle for animals with sprawling-erect posture

  14. The importance of a twisting ankle for animals with sprawling-erect posture

  15. Buttress-erect* Rotation Pillar-Erect Buttress-erect Rotation Hinge Buttress-erect Rotation Crocodylomorpha “Rauisuchia” Ornithosuchidae Ornithodira Crurotarsi Sprawling/Semi-erect Crown-clade Archosauria Hinge Basal archosaurs Archosauria buttress-erect = parasagittal

  16. Buttress-erect* Crocodylomorpha Rotation Late Triassic Terrestrisuchus Saltoposuchus BIPEDAL!/TERRESTRIAL! Terrestrisuchus Saltoposuchus A return to aquatic environments was more recent for crocodylomorphs

  17. Saurischia Ornithischia Pterosauria Dinosauria (later) Ornithodira

  20. Dinosaur expansion: multiple models Competitive Replacement Scenario Opportunistic Scenario (Gradual) (Abrupt)

  21. DINOSAURS

  22. Dinosaur synapomorphies (parasagittal stance) A) Crest on humerus B) Shelf on top surface of ilium C) Perforated acetabulum D) Tibia w/ expanded end E) Ascending astragular process on front surface of tibia

  23. DINOSAURS Herrerosaurus Heterodontosaurus Lagosuchus

  24. Basal Dinosaurs Eoraptor Pisanosaurus Herrerosaurus Coelophysis

  25. Ornithischians!

  26. Lesothosaurus ‘Cheeky’ saurs

  27. Basal Ornithodiran condition Head Tail Heterodontosaurus Shared, derived traits of skull Predentary Low jaw joint Palpebral bone: EAGLE EYE! Deep set cheek teeth Hip shared, derived, trait ‘Opisthopubic pelvis’

  28. Basal Ornithodiran condition Head Tail Heterodontosaurus Shared, derived traits of skull Predentary Low jaw joint Palpebral bone: EAGLE EYE! Deep set cheek teeth Hip shared, derived, trait ‘Opisthopubic pelvis’

  29. Other shared, derived traits At least 5 sacral vertebrae Ossified tendons above sacral region Frontal process on illium Lesothosaurus

  30. How do mammals chew? Front: Cropping Diastem : Manipulation by tongue Cheek teeth: Grinding (occluding) Coronoid Process ~ Muscle attachments Inset molars for cheeks ~ keep food in mouth

  31. How do mammals chew? Front: Cropping Diastem : Manipulation by tongue Cheek teeth: Grinding (occluding) Coronoid Process ~ Muscle attachments Inset molars for cheeks ~ keep food in mouth

  32. Edmontosaurus Ornithopod How did Ornithischians chew? In very similar ways Front: Cropping: carried out by keratin RAMPHOTHECA Diastem: Manipulation by tongue Cheek teeth: Grinding! Dental Batteries Coronoid Process ~ Different shape, different muscle attachments Inset molars for cheeks ~ keep food in mouth

  33. Traveling force Small area, large force Broadly distributed force Large area, less force How did Ornithischians chew? The Angle of the jaw. Scissors vs. Pliers

  34. Basal Ornithischians Pisanosaurus Lesothosaurus Everything else in Ornithischia is in Genasauria Chewing

  35. Lesothosaurus Heterodontosauridae ‘Cheeky’ saurs

  36. Heterodontosaurids: Not Primitive... unique chewing. Three kinds of teeth Anterior: Snipping/Cropping Posterior: Chewing Tusks: Potentially display/courtship

  37. Chevrotain Heterodontosaurids: Not Primitive... unique chewing. Three kinds of teeth Anterior: Snipping/Cropping Posterior: Chewing Tusks: Potentially display/courtship

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