Dinosaur Anatomy: Size, Skeletons, and Hip Structures

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Questions and Answers

Which of the following environments is LEAST likely to preserve fossils well, based on common preservation factors?

A dry, open plain with low sedimentation rates and exposure to the elements. (correct)
A marine environment with high sedimentation rates.
A river delta with consistently wet conditions and high sediment deposition.
A wetland area with low oxygen levels and a high water table.

Compared to modern organisms, how do the sizes of most dinosaurs generally compare to mammals we see today?

Most dinosaurs were around the same size as mammals we see today, such as rhinos, hippos, elephants, and giraffes. (correct)
Most dinosaurs were significantly larger than modern mammals, like whales.
Most dinosaurs were smaller than a chicken.
Most dinosaurs were much larger than any land animal today, dwarfing even elephants.

During fossil excavation, after a bone is discovered but before its removal, what is the MOST crucial initial step?

Thoroughly record the bone's location and orientation within the quarry. (correct)
Wrap the bone in a dry cloth to prevent moisture damage.
Carefully remove any surrounding matrix to fully expose the bone.
Immediately apply a consolidant to strengthen the bone's surface.

A paleontologist discovers a dinosaur bone where the original bone material has been completely replaced by silica. What type of fossil preservation is this an example of?

Replacement (B) Signup and view all the answers

Which of the following geological features represents a hole commonly found in dinosaur skulls, located in front of the eye socket?

Antorbital fenestra (C) Signup and view all the answers

Why is it important to apply wet paper towels to a dinosaur bone before encasing it in plaster and burlap for removal from a quarry?

To create a protective barrier that allows for easier separation of the plaster from the bone during preparation. (C) Signup and view all the answers

If a paleontologist discovers a set of vertebrae from the hip region of a dinosaur skeleton, what term would they use to classify these bones?

Sacral (D) Signup and view all the answers

Which of the following best describes the primary difference between Saurischian and Ornithischian dinosaurs based on their pelvic structures?

Saurischians have a 'lizard hip' with the pubis pointing downwards, while Ornithischians have a 'bird hip' with the pubis pointing backwards. (B) Signup and view all the answers

Which characteristic of a dinosaur's teeth would MOST strongly suggest it was an herbivore?

Flat, broad surfaces for grinding plant matter. (E) Signup and view all the answers

A paleontologist examines the jaws of a newly discovered fossil and observes adaptations for durophagy. Which feature would MOST strongly support this conclusion?

Powerful jaws and robust teeth designed for crushing hard shells. (A) Signup and view all the answers

Which of the following features is most characteristic of Ankylosaurus?

A tail club and osteoderms (armor) (D) Signup and view all the answers

If a Tyrannosaurus rex tooth is lost, how long would it take for a replacement tooth to grow?

1-2 years. (A) Signup and view all the answers

How do paleontologists determine where muscles attached to dinosaur bones, given that soft tissues are rarely preserved?

By using birds and crocodiles to see where their muscles attach and extrapolating to dinosaurs (B) Signup and view all the answers

You discover a set of fossilized teeth. They're sharp and jagged. What kind of feeding strategy did this animal most likely have?

Carnivore (B) Signup and view all the answers

What can melanosomes within fossilized feathers tell paleontologists about dinosaurs?

The pigment and coloration of the dinosaur's feathers (C) Signup and view all the answers

Why is rapid burial considered essential for the preservation of dinosaur soft tissues?

It protects the tissues from scavengers and decomposition. (D) Signup and view all the answers

How does the cube-square law relate to gigantothermy in dinosaurs?

The cube-square law describes the relationship between volume and surface area affecting temperature, which allowed large dinosaurs to maintain a stable internal temperature via gigantothermy. (D) Signup and view all the answers

Why was it necessary for dinosaur eggs to have relatively thin shells, despite the need for protection?

Thin shells allowed for efficient oxygen exchange between the egg and the environment. (D) Signup and view all the answers

Which of the following correctly links a dinosaur with its method of processing plant material?

Ceratopsians - Dental battery (C) Signup and view all the answers

What is the primary purpose of using histology in the study of dinosaur bones?

To observe the internal structure of the bone under magnification to understand growth and age. (A) Signup and view all the answers

Which of the following is the MOST accurate description of gastroliths and their function?

Swallowed stones stored in a muscular pouch to aid in grinding food. (C) Signup and view all the answers

What do lines of arrested growth (LAGs) in dinosaur bones indicate about the animal's life?

The dinosaur experienced seasonal periods of limited resources or slowed growth. (D) Signup and view all the answers

Which of the following inferences about dinosaur locomotion can be BEST derived from ichnofossils?

Relative speed and size. (A) Signup and view all the answers

What does the presence of an external fundamental system (EFS) in a dinosaur bone signify?

The dinosaur had reached skeletal maturity and stopped growing. (A) Signup and view all the answers

Which of the following characteristics is more indicative of a juvenile dinosaur compared to an adult?

Relatively shorter limbs. (A) Signup and view all the answers

An animal with graviportal limbs is MOST likely adapted for which type of lifestyle?

Supporting great weight at the cost of speed. (D) Signup and view all the answers

How does the point of attachment of the caudofemoralis muscle on the femur relate to a dinosaur's locomotion?

A higher attachment point allows for faster leg swings but quicker fatigue. (C) Signup and view all the answers

What is the significance of medullary bone in female dinosaur fossils?

It indicates the dinosaur was storing calcium to produce eggs. (B) Signup and view all the answers

If a dinosaur grew isometrically throughout its life, how would its proportions change as it aged?

Its proportions would remain the same. (B) Signup and view all the answers

If a paleontologist discovers a dinosaur fossil with long lower leg bones and evidence of walking primarily on its toes, which of the following locomotor styles would be MOST likely?

Cursorial (B) Signup and view all the answers

Considering the position of the trochanter on the femur, which of the following dinosaurs was MOST likely the better long-distance runner?

A Hadrosaur with a caudofemoralis attached in the middle of the femur. (C) Signup and view all the answers

How can osteons provide insights into whether a dinosaur was warm or cold-blooded?

The arrangement of osteons differs between endotherms and ectotherms. (D) Signup and view all the answers

Flashcards

Dinosaur Sizes Comparison

Dinosaurs can be compared to modern organisms based on size, being larger than elephants but smaller than chickens.

Major Dinosaur Bones

Key bones include vertebrate (backbone), skull, and limb bones such as humerus and femur.

Pelvic Types of Dinosaurs

There are two major pelvic types: Saurischians (lizard hips) facing down, and Ornithiscians (bird hips) facing back.

Theropoda Features

Theropoda dinosaurs are identified by their bipedal stance and characteristic features such as clawed hands and beak-like mouths.