Lesson 1: appearances and anatomy Flashcards
(79 cards)
Paleontology definition
is the study of all prehistoric life. Knowledge primarily comes from fossils
definition of fossils and what they include
means "dug up." Any preserved evidence left behind by a prehistoric organism. include: Footprints Eggshells Coprolites (fossil poop) Skin and feather impressions Bones
bones definition
Bones are partially made of minerals, which do not decay as easily as flesh and other soft tissues. Animals may store a valuable mineral resource, such as calcium, by growing a new bone deposit or by increasing the density of already existing bone
adaptations definition
Traits that have evolved because they serve specific functions.
dinosaur timeline
Lived in the Mesozoic Era spanned from 248mya to 65mya which included the Triassic, Jurassic, and cretaceous period
convergent evolution definition
The process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities
Example: both birds and bugs fly (similar traits to adapt) but are different species and not related to each other (independently evolve)
cladistics ‘family tree’
groups can be lumped together based on shared characteristics (homologous traits, not analogous traits)
evolution of birds
inherited obligate bipedalism from theropod ancestor
4 types of reptiles
- dimetrodon (292-279mya) (not dinos)
- pterosaurs (not dinos)
- tetrapods
- archosauria
extant definition
meaning living
2 groups of archosaurs
- Crurotarsi (shank ankle) crocs and relatives. peg and socket gives rotation and sprawling capability
- Ornithodira (bird neck) dino, pterosaurs, birds. Mesotarsal ankle - simple hinge joining between the lower leg and the ankle bones; erect stance; maneuverability (fast), but lacks stability
non-amniotic egg
The yolk is represented by the yellow shape below the embryo
Fish egg. The egg is composed of a series of jellylike layers that protect the developing embryo from desiccation, pathogens and, to a limited extent, predators. Surrounding the embryo is a structure called the vitelline membrane
amniotic egg
An air-breathing egg characterized by a shell and extraembryonic membranes
Reptiles, birds, and mammals all have amniotic eggs
centrum definition
A vertebra has a spool- or disk-shaped body
neural arch
Above the centrum is the neural arch, which covers the neural canal
Is the opening in each vertebra, through which the spinal nerves run
Two common types of vertebral processes
1.Transverse processes.
Which extend from the lateral sides of the vertebrae
2. Spinous processes.
Which extend upwards from the neural arch
vertebral processes
Vertebral processes provide attachment surfaces for muscles and sometimes provide articulation surfaces for ribs
cervical vertebrae
Vertebrae in the neck. often have extra-large openings for blood and nerve channels and are adapted to support the weight of an animal’s head
dorsal vertebrae
Vertebrae in the back. often have tall spinous processes and large rib articulation surfaces
sacral vertebrae
Vertebrae in the hips. Because the pelvic bones in terrestrial vertebrates serve as solid anchors for powerful leg muscles, the pelvic bones (later discussed in detail) are fused to the sacral vertebrae
Sacrum
To further increase the strength of the hips, the sacral vertebrae are also fused with one another and form a single solid bone structure
Caudal vertebrae
Vertebrae in the tail
Chevrons
Protect a large blood and nerve channel and provide support for tail muscles
Gastralia
Some dinosaurs had gastralia, or “belly ribs”
Are small ribs positioned across a dinosaur’s underbelly, underneath the ribcage
