Podcast Beta
Questions and Answers
What is a distinguishing feature of Oryctodromeus?
Why is the systematics of basal ornithopods considered volatile?
What time period do Oryctodromeus and other ornithopods generally belong to?
What can be inferred about Basal Iguanodontoidea and Hadrosauridae based on their classification?
Signup and view all the answers
What is the significance of Burianosaurus augustai's discovery?
Signup and view all the answers
What is the significance of Yandusaurus in the context of Ornithopoda?
Signup and view all the answers
What distinguishes basal ornithopods from euornithopods?
Signup and view all the answers
Which of the following statements is true about the size of ornithopods?
Signup and view all the answers
What evolutionary period is associated with the emergence of Ornithopoda?
Signup and view all the answers
Which of the following taxa is classified as a basal ornithopod?
Signup and view all the answers
What is a defining feature of Lambeosaurinae hadrosaurids?
Signup and view all the answers
How many individual teeth can the dental battery of hadrosaurids contain?
Signup and view all the answers
What distinguishes hadrosaurid teeth from those of other vertebrates?
Signup and view all the answers
Which of the following features is NOT associated with hadrosaurids?
Signup and view all the answers
During which geological period did hadrosaurids exclusively exist?
Signup and view all the answers
How do hadrosaurids achieve continuous grinding of food?
Signup and view all the answers
What is the function of replacement teeth in hadrosaurids?
Signup and view all the answers
How does the complexity of hadrosaurid teeth compare to that of mammals?
Signup and view all the answers
What characteristic is NOT associated with Iguanodontoidea?
Signup and view all the answers
Which of the following statements about Tenontosaurus is true?
Signup and view all the answers
What is a distinguishing feature of Hadrosauridae?
Signup and view all the answers
How long could Iguanodon grow?
Signup and view all the answers
What ecological role did Hadrosauridae play in their environment?
Signup and view all the answers
What evidence suggests social behavior among Iguanodon?
Signup and view all the answers
Which dinosaur is associated with having a toothless premaxilla?
Signup and view all the answers
Deinonychus is suggested to have engaged in what kind of hunting behavior?
Signup and view all the answers
The term 'unguals' refers to which part of the Iguanodontia?
Signup and view all the answers
Which feature is unique to the Hadrosauridae family?
Signup and view all the answers
What describes the likely social behavior of hadrosaurs during the Late Cretaceous?
Signup and view all the answers
What type of evidence supports the idea of social behavior in hadrosaurs?
Signup and view all the answers
What is a significant characteristic of hadrosaur jaws?
Signup and view all the answers
What does the evidence suggest about the breeding behavior of derived ornithopods like hadrosaurs?
Signup and view all the answers
What is indicated by the presence of large subadult and adult-sized bones in hadrosaur bonebeds?
Signup and view all the answers
Which hadrosaur species is mentioned as having evidence of child-rearing behaviors?
Signup and view all the answers
How many disarticulated elements have been found in some hadrosaur bonebeds?
Signup and view all the answers
What type of biomechanical process was maximally efficient in hadrosaurs?
Signup and view all the answers
Study Notes
Ornithopoda
- Oldest fossil: Yandusaurus (Middle Jurassic)
- Survived until the end of the Cretaceous
- Known from all continents
- Size range: 2 to 14 m in length
- Basal members: Agile bipeds
- Large derived forms: Mostly quadrupedal
- Basal ornithopods (non-euornithopods): 4 hoofed-toes for weight support
- Euornithopoda: 3 functional hoofed-toes
- Systematics of basal ornithopods and ornithischians is volatile due to fragmentary specimens and similar morphology
Basal Ornithopods
- Burianosaurus augustai: Cenomanian of the Czech Republic, known from one femur
Orodrominae
- Early to Late Cretaceous, NA & Asia
- Oryctodromeus: First dinosaur to show burrowing and denning behavior
- An adult and two juveniles found in a den
- Bipedal with forelimbs adapted for digging
Basal Iguanodontians
- Tenontosaurus: Common dinosaur in the Early Cretaceous of western NA
- 75% of Tenontosaurus localities contain Deinonychus remains, suggesting pack hunting
Iguanodontoidea
- Longer, broader snouts
- Larger size
- Thumb spike (digit I)
- Digit V opposable
- Digits II & III robust with large, rounded, weight-bearing unguals
Iguanodontoidea: Basal Iguanodontoideans
- Iguanodon: Early Cretaceous, Europe; adults up to 10 m, ~3 tons
- Named in 1825 by Gideon Mantell
- 38 skeletons from a Belgian Coal mine
- 15 individuals from a bonebed in Germany: Evidence for sociality
- Forelimbs ~75% the size of hindlimbs
Iguanodontoidea: Basal Iguanodontoideans
- Ouranosaurus: Early Cretaceous, Niger; ~8 m in length, ~4 tons
- Toothless premaxilla; one row of replacement teeth
- Small crest in front of the skull
- Tall neural spines
Hadrosauridae
- Cretaceous; globally distributed
- Larger size: > 14 m in length (Shantungosaurus)
- Bipedal and quadrupedal capability
- Dominant mode: Quadrupedal
- "Duck bill" is a flaring of the premaxilla and predentary covered by a keratin-covered beak (rhamphotheca)
- Evidence for gregariousness and herding behavior
Hadrosauridae
- Two major clades: Hadrosaurinae and Lambeosaurinae
- Up to 15 m in length; 2 m skulls
- Exclusively Late Cretaceous in age
Hadrosauridae: Hadrosaurinae
- "Solid-crested"
Hadrosauridae: Lambeosaurinae
- "Hollow-crested"
- Cranial crest formed by the nasal bone
- Tall, symmetrical lancelet tooth
- Dental battery with three or more teeth
Hadrosaurids vs. Basal Iguanodontia
- Further expansion of the snout ("duck bill")
- Increase in the number of tooth positions
- Grinding dental battery with a continuous grinding surface
- Teeth with greater structural complexity
Hadrosauridae: Dentition
- Up to 1400 diamond-shaped, tightly packed teeth
- 5 replacement teeth constantly pushing
Hadrosauridae: Dental Histology
- Each tooth is comprised of at least 6 different dental tissues
- More complex than teeth of mammals, including horses
- Sophisticated dental system
Hadrosauridae: Abundance
- Most abundant dinosaurs in the Late Cretaceous of NA
- Moved in large herds
- Efficient jaws maximized energy from plant resources
Hadrosauridae: Social Behaviour (Bonebeds)
- Monodominant hadrosaur bonebeds are known from NA and Asia
- Dozens of Edmontosaurus bonebeds from the L Campanian and Maastrichtian of Canada and the US
- Some preserved >10,000 disarticulated elements
- Large subadults and adult-sized bones dominate
- Evidence for social and/or herding behavior
Hadrosauridae: Reproduction
- Not much evidence from basal ornithopods
- Derived ornithopods (Hadrosauridae) show evidence of child-rearing and parental care (e.g., Maiasaura, Hypacrosaurus)
- Nesting sites reused for multiple generations
- Evidence for 1 and 2 year juvenile cohorts
Hadrosauridae: Reproduction (Hypacrosaurus)
- Hypacrosaurus Nesting Site at Devil's Coulee, AB
Hadrosauridae: Soft Tissue Preservation
- Edmontosaurus regalis (L. Cret)
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the fascinating world of Ornithopoda, a group of dinosaurs that thrived from the Middle Jurassic to the end of the Cretaceous. This quiz covers key fossil findings, systematic challenges, and notable species such as Yandusaurus and Oryctodromeus. Discover their adaptations for survival and the evolution of their morphology.