Name:

ANT 3514 – Intro to Biological Anthropology

Lab 7

Primate Evolution

Week of February 23, 2005

OWM

Streps Tarsiers NWM colobines cercop gibbons orang African apes Hominids

The nodes on a cladogram represent shared derived features that unite a natural group of species to the exclusion of others. We will go over how this cladogram was constructed in lab.

1- postorbital bar, convergent orbits

2- partial postorbital closure, loss of tapetum lucidum, development of haplorhine nose

3- complete postorbital closure, more complex (elaboration) placenta

7- fused wrist bones, genetic/molecular similarities, enlarged ovaries, changes in premaxilla, shortened canines

**At home, list one trait for the each following nodes:

4- ______

5- ______

6- ______


STATION 1: The earliest Primates? Plesiadapsis & Purgatorius

Fossils of the earliest primate-like mammals exist from the Paleocene epoch (58-65 mya). These fossils are found in North America and Europe. There is disagreement over whether or not these are actually early primates. Take some time to look at the drawing of the plesiadapiform skulls, the plesiadapiform tooth cast and the tree shrew skull. Use these items and your book to answer the following questions:

What are two primate characteristics these fossils possess?

1.______

2. ______

What are two non-primate characteristics?

1.______

2.______

STATION 2: The earliest Primates: Eocene Radiation

The start of the Eocene epoch (58 mya) coincides with a period of adaptive radiation for the earliest well-defined primate species (nearly 60 genera, this is four times greater than the amount of prosimian diversity today). Two extinct families: Adapidae and Omomyidae, help to group the earliest primates. The adapids are thought to be ancestral to present day lemurs and lorises, whereas the omomyids are most likely ancestral to tarsiers. Adapids and omomyids were sympatric and found in North America and Europe.

Compare the adapid skull, lemur skull and tarsier skulls. Use these skulls and the laminated drawing to answer the following questions:

What are two traits the adapid and the lemur share?

1.______

2. ______

Name and describe two differences between the adapid and the tarsier.

1.______

2.______


STATION 3: Early Anthropoids

The Oligocene epoch began 35 mya and marked by a great deal of geologic and climatic change. This time period also represents a major gap in the fossil record. However, the Fayum deposits in Western Egypt are an exception (additional scattered remains have been found worldwide). One of the earliest known and best described catarrhine monkeys from this time is Aegyptopithecus. Aegyptopithecus belongs to the family Propliopithcidae. Propliopithecids have been found in Africa, Asia and South America.

Other anthropoids found at Fayum, but thought to precede the split between platyrrhines and catarrhines are Parapithecus and Apidium.

Examine the Aegyptopithecus, Parapithecus, Apidium, capuchin, howler and baboon skulls, along with the laminated picture in order to answer the following questions:

Which of the fossils are more like new world monkeys, and why?

  1. ______

Which is more like an old world monkey and why?

1. ______

Name and describe one similarity and one difference between the Aegyptopithecus and the baboon.

  1. ______
  1. ______

**What do these similarities and differences tell you about the place of Aegyptopithecus on a cladogram of extant and extinct primates?

STATION 4: Fossil Apes

The beginning of the Miocene epoch (25 mya) marks the appearance of the first apes. At this time, apes shared a great deal of morphological similarities with monkeys. One of the first ape genera includes Proconsul (20-17 mya). Another later genus, Sivapithecus (12-7 mya), is most commonly thought of as the ancestor of orangutans.

Examine the Proconsul, Sivapithecus, Gigantopithecus, Oreopithecus, cercopithecine, orangutan and chimpanzee specimens in order to answer the following questions:

Name and describe two differences between Proconsul and the cercopithecine.

  1. ______
  1. ______

Name and describe two similarities between Sivapithecus and the orangutan

  1. ______
  1. ______

Name and describe two differences between Sivapithecus and the chimpanzee.

  1. ______
  1. ______

**Homework:

Place the following fossils in the appropriate place on the chart of geologic time (draw lines):

Sivapithecus

Proconsul

Plesiadapsis

Purgatorius

Adapid
Omomyid
Aegyptopithecus /

Reading Question:

1. Based on modern analysis of the fossils, what conclusions have been reached about the anatomy and lifestyle of Gigantopithecus? (Cha. 21)


Landmarks

Most definitions are from http://www.modernhumanorigins.com/definitions.html

Femur

greater trochanter: Very large process on the lateral and proximal end of the femur shaft, for the attachment of muscles that stabilize the hip during one-legged balance (whether in standing or in bipedal locomotion).

lesser trochanter: Large blunt process on the posterior face of the femoral shaft, just below the neck, for attachment of muscles that flex the thigh.

condyle: A smooth, rounded articular surface that is found in pairs (lateral and medial); distal end of femur.

Pelvis

ilium (iliac blades): The side, or broad and flat blade of the innominate, forming its upper portion

ischium: The lower rear bone of the innominate.

pubis: The front of the pelvis, formed by the parts of the innominate that meet at the midline

anterior iliac spines: In hominids, two bony projections (superior and inferior) for muscles to attach that extend the leg, protruding from the front edge of the ilium. Sartorius attaches on the anterior iliac spine and rectus femoris (one of the quadriceps) on the anterior inferior spine.

acetabulum: Joint depression in the os coxa into which the head of the femur fits, the socket in the ball-in-socket hip joint. The three bones of the os coxa (ilium, ischium, pubis) meet in the acetabulum.

greater sciatic notch: U-shaped notch at the back of the innominate characteristics of bipedal hominid pelves caused by the rearward and inferior displacement of the sacrum relative to the ape anatomy.

obturator foramen: A space at the front of the pelvis enclosed by the pubis and ischium.


Cranium

asterionic notch: The notch at the bottom-rear of the parietal bone, located over the mastoid process.

bowing (limb shaft bowing): Curvature of the long bone shaft in the anterior-posterior plane

breadth of molars: refers to the buccal (cheek)- lingual (tongue) distance of the molar

calotte: the bones of the cranial vault, the calvaria without the cranial base

calvaria (calvarium): The bones of the cranium without the face or mandible.

canine fossa: A vertical furrow on the maxilla under the infraorbital foramen, extending toward the base of the zygomatic process of the maxilla and to the side of the nose.

canine jugum (juga): Vertical ridge in the maxilla caused by an enlarged canine root.

facial buttressing (anterior pillars): Two vertical columns of bone, on either side of the nasal aperture, extending above and lengthening the pilaster of bone surrounding the canine roots.

facial dishing: A condition in some hominid faces where the nasal bones and the borders of the piriform aperture are recessed relative to the cheeks, making the midface area concave.

foramen magnum: The large opening in the occipital bone on the base of the skull through which the spinal cord passes to join the base of the brain.

frontal trigone: A concave smooth triangular area on the frontal bone just behind the orbits. Its base is formed by the supraorbital torus and its apex by converging temporal lines. To be distinguished from lateral frontal trigone.

glabella: A place on the midline of the frontal bone between the browridges, superciliary arches, or upper orbital borders

inion: The center of the tuberculum linearum, a protuberance of varying expression that develops where the superior nuchal lines meet at the sagittal plane. It is not necessarily what is called the external occipital protuberance (although this describes what it is) which occurs above it, at or below where the supreme nuchal lines meet at the midline

interorbital distance: Distance between the orbits.

lateral frontal trigone: A backward-facing triangular form to the lateral-most part of the supraorbital torus. The apex is created by a prominent temporal ridge, and the torus is thicker at the trigone than it is medially. To be distinguished from the frontal trigone.

malar: See zygomatic

mandibular (glenoid) fossa: Joint for the mandibular articulation with the skull, a depression on the base of the temporal bone, just in front of the ear opening, into which the mandibular condyles fit.

mastoid process: A pyramid-shaped prominence of cancelous bone on the temporal bone behind the external auditory meatus. Muscles that extend and turn the head attach on it.

nasal spine (anterior): The thin projection of bone at the midline on the lower nasal margin, holding the cartilaginous center of the nose.

nasoalveolar clivus: Portion of the premaxilla extending from the nasal cavity to the incisor root sockets.

nuchal torus (occipital torus): A thickened bony prominence extending transversely across some or all of the back of the head, on the occipital bone, reflecting the pattern of muscle use as it separates the nuchal plane below from the occipital plane above.

occipital bun: A backward extension of the cranial rear in the form of a protuberance bounded by the nuchal plane below, a shaft vertical face for the occiput behind, and a flat surface above (lambdoidal flattening).

piriform aperture: The pear-shaped nasal opening of the skull; anterior nasal aperture

pneumatization: Air spaces in cranial bones such as the mastoid area, or nasal sinuses.

postorbital constriction: Narrowing of the (frontal and sphenoidal walls of the) skull behind the orbits, where they form the inner wall of the temporal fossa.

premaxilla: Front part of the palate and subnasal maxilla, anterior to the middle of the canine roots and housing the incisors.

retromolar gap (space): A space or gap at the rear of a mandible between the back of the last molar and the anterior edge of the ascending ramus where it crosses the alveolar margin.

squama: The flat portion of a cranial bone

subnasal alveolar process: Part of the anterior maxilla below the nose, housing the roots of the upper incisors.

subnasal plane: when the subnasal alveolar process forms a flat, level surface

superciliary arches: Smoothly rounded bulges of bone found on the frontal bone of the skull at its center and extending over the inner portion of the upper orbital border.

suprainiac fossa: An elliptical depression on the occiput above the superior nuchal line, or inion

supratoral sulcus: A broad depression or groove between the browridges and the frontal bone, creating an angle between the top of the browridge and the front of the orbital squama.

temporal fossa: The space enclosed by the side of the skull and the zygomatic arch, which is occupied by the temporalis muscle as it passes from its mandibular attachment to its attachment on the cranium.

temporonuchal crest: A compound crest on the back of the skull formed by convergence of the temporal line of the nuchal crest.

tympanic bone (tympanic plate): The portion of the temporal bone that encloses the inner ear.

uniform incisors: all of the incisors are same size and shape

zygomatic arch: Bony arch on the lateral part of the cheek formed by projections of the zygomatic bone and the temporal bone, enclosing the fibers of the temporalis muscle and for attachment of the masseter muscle.