Lab 18: Dinosaurs (Phylum Chordata)

Questions and Answers

When did dinosaurs evolve (era)?

The Mesozoic era

Dinosaurs are diapsid reptiles.

True

Marine and flying dinosaurs used to exist.

False

When were dinosaurs recognized as reptiles?

In the 1800s Signup and view all the answers

Who is Robert Plot?

A curator of a museum in England in the 1670s who published a book with an illustration of a large thighbone. Signup and view all the answers

Which dinosaur was the first to ever be described scientifically?

Megalosaurus Signup and view all the answers

Who discovered large 'teeth' from the remains of an Iguanodon?

Mary Ann Mantell Signup and view all the answers

What are the basic types/orders of dinosaurs?

Order Saurischia and Order Ornithischia Signup and view all the answers

What is the classification of dinosaurs starting from the phylum?

Phylum Chordata, Class Reptilia, Subclass Diapsida, Superorder Archosauria, Order Saurischia, Order Ornithischia Signup and view all the answers

What is the description of the subclass Diapsida?

Diapsids are amniotes having a skull with two temporal openings. Signup and view all the answers

What is the description of the superorder Archosauria?

The 'ruling' reptiles, mostly terrestrial with some specialized for flight. Signup and view all the answers

What is the description of the order Saurischia?

Mesozoic dinosaurs that include bipedal carnivores and quadrupedal herbivores. Signup and view all the answers

What is the description of the suborder Sauropodomorpha?

Includes Brachiosaurus, Apatosaurus, and Diplodocus; huge, herbivorous quadrupeds. Signup and view all the answers

What is the description of the suborder Theropoda?

Includes Tyrannosaurus, Deinonychus, and Velociraptor; carnivorous and bipedal. Signup and view all the answers

What is the order Ornithischia?

Includes Stegosaurus, Triceratops, and Parasaurolophus; all are herbivorous and extinct. Signup and view all the answers

Dinosaurs stood _____ with their knees and feet under their bodies.

Erect Signup and view all the answers

Plesiosaurus is a dinosaur.

False Signup and view all the answers

Mosasaurus is not a dinosaur.

True Signup and view all the answers

What caused the Cretaceous Extinction?

Three hypotheses: environmental challenges, a massive super volcano, and impact events. Signup and view all the answers

Who is the scientist who discovered large versions of modern reptiles between 1819 and 1824?

William Buckland Signup and view all the answers

Who is Richard Owen?

A scientist who concluded that some reptile fossils were similar and unlike anything seen in modern day. Signup and view all the answers

Study Notes

Dinosaur Evolution and Classification

Dinosaurs evolved during the Mesozoic era.
Dinosaurs belong to the diapsid group of reptiles.
Dinosaurs were recognized as reptiles in the 1800s.
The first scientifically described dinosaur was Megalosaurus.
Mary Ann Mantell discovered large teeth from an Iguanodon.

Orders and Suborders of Dinosaurs

Dinosaurs are classified into two main orders:
- Order Saurischia:
  - Suborder Sauropodomorpha: Includes massive herbivores like Brachiosaurus and Apatosaurus.
  - Suborder Theropoda: Predatory dinosaurs such as Tyrannosaurus and Velociraptor; bipedal.
- Order Ornithischia: Features bipedal and quadrupedal herbivores like Stegosaurus and Triceratops.

Taxonomy and Anatomy

Taxonomy of dinosaurs starts with Phylum Chordata, Class Reptilia, and includes:
- Subclass Diapsida: Amniotes with two temporal skull openings.
- Superorder Archosauria: Advanced diapsids, mostly terrestrial with some specialized for flight.
- Order Saurischia and Order Ornithischia are the primary classifications within dinosaurs.
Dinosaurs had an erected posture with knees and feet positioned under their bodies.

Characteristics and Misconceptions

Plesiosaurus and Mosasaurus are not considered dinosaurs.
All known dinosaurs are extinct and had distinct anatomical features.
Order Saurischia consisted of both bipedal carnivores and quadrupedal herbivores.
Order Ornithischia featured advanced, bird-like hip structures.

Extinction Theories

The Cretaceous extinction event is attributed to several hypotheses:
- Dinosaurs likely faced environmental challenges that diminished their adaptability.
- Super volcanic activity may have released ash into the atmosphere affecting climate.
- Impact events, such as asteroids, contributed to the extinction scenario.

Notable Scientists in Paleontology

Robert Plot was a curator who mistakenly attributed a large thighbone to a giant human.
William Buckland discovered large reptile fossils between 1819 and 1824.
Richard Owen recognized that the fossils represented a unique group of reptiles not seen in modern times.

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Description

Test your knowledge on dinosaurs with these flashcards from Lab 18. Learn about their evolution during the Mesozoic era, classification as diapsid reptiles, and historical recognition in the 1800s. Perfect for anyone interested in the fascinating world of dinosaurs!