Podcast
Questions and Answers
What is the characteristic feature of the Saurischia group?
What is the characteristic feature of the Saurischia group?
- Turtle-hipped
- Mammal-hipped
- Bird-hipped
- Lizard-hipped (correct)
Which of the following is NOT a likely ancestor of dinosaurs?
Which of the following is NOT a likely ancestor of dinosaurs?
- Lesothosaurus
- Marasuchus
- Pterosaurs (correct)
- Eoraptor
What is the likely stance of the ancestors of dinosaurs?
What is the likely stance of the ancestors of dinosaurs?
- Facultative quadrupedal
- Obligate bipedal (correct)
- Facultative bipedal
- Obligate quadrupedal
Which group of dinosaurs is characterized by a full domed head?
Which group of dinosaurs is characterized by a full domed head?
What is the purpose of the domes in Pachycephalosauria?
What is the purpose of the domes in Pachycephalosauria?
What is the estimated weight of Triceratops?
What is the estimated weight of Triceratops?
Which group of dinosaurs is characterized by a flat-headed skull?
Which group of dinosaurs is characterized by a flat-headed skull?
What is the characteristic feature of the Ankylosauria group?
What is the characteristic feature of the Ankylosauria group?
What is the likely reason for the frequent occurrence of lesions in Pachycephalosauria?
What is the likely reason for the frequent occurrence of lesions in Pachycephalosauria?
What characteristic is common to all species of Maniraptor?
What characteristic is common to all species of Maniraptor?
Which family of Sauropodomorpha dominated by the late Cretaceous?
Which family of Sauropodomorpha dominated by the late Cretaceous?
What type of feathers are characterized by having a central shaft?
What type of feathers are characterized by having a central shaft?
What is the name of the largest land animal to have ever existed?
What is the name of the largest land animal to have ever existed?
What is the purpose of the structures of fossilized melanosomes?
What is the purpose of the structures of fossilized melanosomes?
What is the name of the group of basal Theropods that lived around 230+ mya?
What is the name of the group of basal Theropods that lived around 230+ mya?
What is the name of the first fossil of Archaeopteryx that was found in 1860?
What is the name of the first fossil of Archaeopteryx that was found in 1860?
What is the name of the group of Sauropods that includes Brachiosaurus?
What is the name of the group of Sauropods that includes Brachiosaurus?
What is the name of the ancient archosaur lineage that produces beta-keratin?
What is the name of the ancient archosaur lineage that produces beta-keratin?
When did the first species of Iguanodon exist?
When did the first species of Iguanodon exist?
Which clade of reptiles includes turtles?
Which clade of reptiles includes turtles?
What is the likely characteristic of the ancestors of all dinosaurs?
What is the likely characteristic of the ancestors of all dinosaurs?
What is the characteristic feature of the Stegosauria group?
What is the characteristic feature of the Stegosauria group?
What is the purpose of the fibroblasts in the bone of Pachycephalosauria?
What is the purpose of the fibroblasts in the bone of Pachycephalosauria?
Which of the following is an early saurischian dinosaur?
Which of the following is an early saurischian dinosaur?
What is the characteristic feature of the Ankylosauria group?
What is the characteristic feature of the Ankylosauria group?
Which group of dinosaurs is characterized by having a lizard-hipped pelvis?
Which group of dinosaurs is characterized by having a lizard-hipped pelvis?
What is the estimated time range of the Lesothosaurus dinosaur?
What is the estimated time range of the Lesothosaurus dinosaur?
Which group of dinosaurs is characterized by having a bird-hipped pelvis?
Which group of dinosaurs is characterized by having a bird-hipped pelvis?
What is the characteristic that distinguishes the skulls of Hadrosaurines from those of Lambeosaurines?
What is the characteristic that distinguishes the skulls of Hadrosaurines from those of Lambeosaurines?
What is the estimated length range of ornithopods?
What is the estimated length range of ornithopods?
What is the name of the largest land animal that ever existed?
What is the name of the largest land animal that ever existed?
What is the name of the group of basal Theropods that lived around 230+ mya?
What is the name of the group of basal Theropods that lived around 230+ mya?
What is the characteristic that all Maniraptors share?
What is the characteristic that all Maniraptors share?
What is the name of the first fossil of Archaeopteryx that was found in 1860?
What is the name of the first fossil of Archaeopteryx that was found in 1860?
What is the name of the family of Sauropodomorpha that dominated by the late Cretaceous?
What is the name of the family of Sauropodomorpha that dominated by the late Cretaceous?
What is the purpose of the structures of fossilized melanosomes?
What is the purpose of the structures of fossilized melanosomes?
What is the characteristic of the feathers found in Maniraptors?
What is the characteristic of the feathers found in Maniraptors?
What is the significance of Crocodiles in the context of feathers?
What is the significance of Crocodiles in the context of feathers?
Study Notes
Synapsids and Mammal-like Reptiles
- Reptilia includes anapsid (turtles) and diapsids (Lepidosauromorpha and Archosauria)
- Synapsids are mammal-like reptiles and mammals
Dinosaurs' Likely Ancestors
- Early thoughts included Pterosaurs as a likely candidate, e.g., Rhamphorynchus
- Marasuchus and Silesaurus are not likely to be ancestors of dinosaurs
- Other alternatives: Eoraptor (an early saurischian, 243 mya), Lesothosaurus (a primitive ornithischian, 220-225 mya)
- Ancestors of dinosaurs were probably obligate bipeds
Saurischia and Ornithischia
- Saurischia (lizard-hipped) and Ornithischia (bird-hipped) are two distinct groups
Stegosauria
- 13 genera from early Jurassic to early Cretaceous
- Peak of diversity in late Jurassic with 7 known species
Ankylosauria
- Nodosauridae and Ankylosauridae families
- Medium to large in size, mostly less than 5m long, but up to 9m
- Patterns of armour used to identify species
Pachycephalosauria
- Full domed, about 10 recognised species
- Flat-headed, number of species unknown
- Frequency of lesions suggest wounding during confrontation
- Domes were used in combat
Ceratopsians
- Triceratops and Styracosaurus
- Triceratops: 6-7 tons, large and well-known monophyletic group
Ornithopods
- Existed from the Early Jurassic until the end of the Cretaceous
- Adult length ranged from 1-2m up to 12m
- Excellent range of fossils collected from across the globe: 80 species known
Iguanodon
- Discovered in 1822 by Gideon and Mary Ann Mantell, Tilgate Forest, West Sussex
Sauropodomorpha
- Brachiosauridae: Brachiosaurus - 22.5m and over 60 tons
- Diplodocidae: Late Triassic - early Cretaceous
- By the late Cretaceous, the Titanosaurs dominated
- Argentinosaurus: biggest land animal ever at 40m and 99-110 tons
Theropoda
- Varied group containing many species from late Triassic until late Cretaceous
- Herrasauria: basal Theropods from 230+ mya, poorly known
- Ceratosauria: fast runners, short limbs often with thickened bones on head
Archaeopteryx
- First fossil found in 1860 from the Solnhofen quarry
- Had many typical Theropod characteristics and pneumatic bones
Maniraptors
- Oldest around 160 mya
- By the end of the Cretaceous, species that looked like modern birds existed
- Possession of feathers is common to all species of Maniraptor
- Feathers: filaments - plumulaceous - pennaceous
- Structures of fossilised melanosomes serve to indicate pigmentation on the animal when alive
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Description
Explore the evolution of dinosaurs and their possible ancestors. Learn about the relationships between reptiles, synapsids, and mammals. Discover the likely candidates that gave rise to these prehistoric creatures.
