EPS SCI 15 Lecture Notes - Lecture 6: Phalanx Bone, Synapomorphy, Metatarsal Bones
29 Apr 2018
School
Department
Course
Professor
Lec 6: Anatomy and Cladistics
April 19
INTRODUCTION TO ANATOMY
●How should we organize life on Earth? How are dinosaurs related to each other?
● taxon (
pl. taxa)
: a grouping of organisms (ex. species, genus, order, etc.)
○ we can define taxa on the basis of characters
that all the members share
○ for fossil taxa,
● Anatomical Directions
○ anterior = front (head)
○ posterior = back (back end)
● Dinosaur Skulls
○ Types of Skulls
■ kinetic
: multiple joints → allows skull to move
in all different directions (allows for large
gapes)
● ex. fish, snakes, most dinosaurs
■ akinetic
: 1 joint → tend to be more robust
(allows for stronger jaw & bite)
Document Summary
Taxa) : a grouping of organisms (ex. species, genus, order, etc. ) We can define taxa on the basis of characters that all the members share. Kinetic : multiple joints allows skull to move in all different directions (allows for large gapes) Akinetic : 1 joint tend to be more robust (allows for stronger jaw & bite) Many dinosaurs have ossified tendons on their vertebral column (esp. in caudal vertebrae) keep it stiffened and allow for strong muscles to attach. Sacral bones in the pelvis are fused together losing flexibility, but has much strength. Arms (forelimbs) and legs (hindlimbs) and their attachments. Pectoral girdle (shoulder-blades) : attaches forelimb (arm) to axial skeleton) not a very strong connection. Scapula holds arms to rest of body. Phalangeal formula : the number of phalanges on each finger (ex. Digits 4 & 5 reduced in dinosaurs (asymmetrical 123 hand) Modifications made to femur (attaches to pelvis) gives dinosaurs their upright posture.
