BIO A 201 - 11.03.25 Evolution of Primates & Early Hominins - Week 7 Flashcards 1

Homo neanderthalensis

• When: Approximately 400,000 to 40,000 years ago.

• Where: Europe and parts of Asia.

• What: An extinct species of the genus Homo, closely related to modern humans. Characterized by a robust build, large brow ridges, and complex cultural behaviors, including toolmaking and burials.

• Brain Capacity: Typically 1,200 - 1,750 cc (often larger than modern humans, relative to body size).

Homo sapiens

• When: Emerged approximately 300,000 years ago to the present.

• Where: Originated in Africa, now globally distributed.

• What: The species name for modern humans, characterized by a highly developed brain, complex language, sophisticated tool use, and symbolic thought.

• Brain Capacity: Typically 1,000 - 1,700 cc, averaging around 1,300 - 1,400 cc.

Homo erectus

• When: About 1.9 million years ago to 110,000 years ago.

• Where: Africa, Asia (e.g., China, Java), and possibly Europe.

• What: An extinct species of hominin known for its upright posture and efficient bipedalism. It was the first hominin to migrate out of Africa and is associated with the Acheulean tool industry.

• Brain Capacity: Varied from about 750 - 1,250 cc.

Homo heidelbergensis

• When: Around 700,000 to 300,000 years ago.

• Where: Europe, Africa, and possibly Asia.

• What: An extinct species of the genus Homo that is considered a potential common ancestor for Neanderthals and modern humans. They used sophisticated tools.

• Brain Capacity: Around 1,100 - 1,400 cc.

Homo rudolfensis

• When: Approximately 1.9 million years ago.

• Where: East Africa (e.g., Koobi Fora, Kenya).

• What: An extinct species of the genus Homo known primarily from fossil remains. Distinguished by a relatively large braincase and a flat, relatively long face. Its taxonomic status is debated, with some classifying it as Australopithecus.

• Brain Capacity: Around 750 cc.

Paranthropus boisei

• When: About 2.3 to 1.2 million years ago.

• Where: East Africa.

• What: A robust australopith species noted for its massive molars, thick enamel, strong jaw, and sagittal crest, adapted for chewing tough, fibrous plant material. Nicknamed "Nutcracker Man".

• Brain Capacity: About 450 - 550 cc.

Homo habilis

• When: About 2.4 to 1.4 million years ago.

• Where: East and South Africa.

• What: An early species of Homo, known as 'handy man,' due to its association with primitive stone tools (Oldowan industry). Possessed smaller teeth than Australopithecus.

• Brain Capacity: Around 550 - 687 cc.

Paranthropus robustus

• When: About 1.8 to 1.2 million years ago.

• Where: South Africa.

• What: A species of the genus Paranthropus known for its strong jaw and large teeth, particularly large molars and premolars, adapted for a diet of tough, fibrous plants.

• Brain Capacity: About 410 - 530 cc.

Homo ergaster

• When: About 1.9 to 1.4 million years ago.

• Where: Eastern and Southern Africa.

• What: An extinct species of the genus Homo, considered by some to be the African form of H. erectus, or possibly an ancestor to modern humans. Known for its adaptability, more slender build, and efficient bipedalism. Debate exists whether it's distinct from H. erectus.

• Brain Capacity: Around 700 - 900 cc.

Australopithecus africanus

• When: About 3 to 2 million years ago.

• Where: South Africa.

• What: An early hominin species exhibiting both ape-like and human-like features, including bipedalism, but with a relatively small brain and large teeth.

• Brain Capacity: About 420 - 510 cc.

Kenyanthropus platyops

• When: Approximately 3.5 to 3.2 million years ago.

• Where: Kenya (Lake Turkana region).

• What: A possible hominin species known for its flat face. Its taxonomic placement is highly debated; some classify it as an Australopithecus or simply as A. afarensis.

• Brain Capacity: Generally estimated to be small, similar to Australopithecus, roughly 400 - 550 cc.

Ardipithecus ramidus

• When: About 4.4 million years ago.

• Where: Ethiopia (Middle Awash Valley).

• What: An early hominin species highlighting mosaic traits of both arboreal apes and terrestrial humans, such as bipedalism on the ground but a grasping big toe for climbing.

• Brain Capacity: Small, around 300 - 350 cc.

Australopithecus garhi

• When: Approximately 2.5 million years ago.

• Where: Ethiopia (Bouri formation).

• What: An extinct hominin species known from fossil remains suggesting a mix of ancestral traits (large teeth) and adaptations, potentially associated with early stone tool use and meat consumption through scavenging.

• Brain Capacity: About 450 cc.

Paranthropus aethiopicus

• When: About 2.7 to 2.3 million years ago.

• Where: East Africa.

• What: An ancient hominin species characterized by a robust cranium, a prominent sagittal crest, and large teeth, suggesting a diet of tough, fibrous foods. Known as the "Black Skull".

• Brain Capacity: About 410 cc.

Australopithecus afarensis

• When: Around 3.9 to 2.9 million years ago.

• Where: East Africa (Ethiopia, Tanzania, Kenya).

• What: A well-known early hominin species, exemplified by the famous 'Lucy' fossil and Laetoli footprints, demonstrating clear evidence of bipedalism, but also possessing ape-like cranial features.

• Brain Capacity: Ranged from about 380 - 550 cc.

Australopithecus anamensis

• When: About 4.2 to 3.9 million years ago.

• Where: East Africa (Kenya, Ethiopia).

• What: An early species of Australopithecus that lived primarily in woodland habitats, demonstrating early forms of bipedalism based on leg bone morphology, while still retaining features for tree climbing.

• Brain Capacity: Likely small, comparable to other early Australopithecus species, around 365 - 370 cc based on limited cranial evidence.

Ardipithecus kadabba

• When: Around 5.8 to 5.2 million years ago.

• Where: Ethiopia (Middle Awash Valley).

• What: An early potential ancestor to humans known from limited fossil remains (teeth and postcrania), suggesting incipient bipedalism based on toe bone morphology. Regarded as a very early hominin.

• Brain Capacity: Not known due to lack of cranial remains.

Orrorin tugenensis

• When: About 6 million years ago.

• Where: Kenya (Tugen Hills).

• What: An ancient hominin species known for bipedal traits inferred from femur morphology, found in a woodland environment. Its status as a direct human ancestor is debated.

• Brain Capacity: Not known due to lack of cranial remains.

Sahelanthropus tchadensis

• When: About 7 to 6 million years ago.

• Where: Chad (Djura desert).

• What: One of the oldest known species in the human lineage, known primarily from a cranium ("Toumaï"). Its anteriorly placed foramen magnum suggests bipedalism, but this is still debated.

• Brain Capacity: Estimated around 320 - 380 cc.

Homo floresiensis

• When: Approximately 100,000 to 50,000 years ago.

• Where: Liang Bua cave, Flores, Indonesia.

• What: An extinct species of small-bodied, small-brained hominin, nicknamed the "Hobbit," known for its diminutive size (about 1 meter tall) and use of stone tools. Its small size is thought to be an example of insular dwarfism.

• Brain Capacity: Extremely small, about 380 - 417 cc.

Homo naledi

• When: Approximately 335,000 to 236,000 years ago.

• Where: Rising Star Cave system, South Africa.

• What: An extinct species of hominin exhibiting a mosaic of primitive and modern features, including a small brain and human-like hands and feet, found in deep cave chambers, suggesting complex burial or body disposal behaviors.

• Brain Capacity: Ranged from about 465 - 610 cc.

Australopithecus sediba

• When: About 1.98 million years ago.

• Where: Malapa Cave, South Africa.

• What: An extinct hominin species exhibiting a mix of Australopithecus and Homo characteristics, providing insight into the transition between these genera. It had long arms and human-like pelvis and hands.

• Brain Capacity: Relatively small, around 420 cc.

Homo antecessor

• When: About 1.2 million to 800,000 years ago.

• Where: Atapuerca (Gran Dolina), Spain.

• What: An extinct hominin species proposed as a common ancestor for Neanderthals and modern humans, or as an early European offshoot. Known for its mix of modern and archaic features, including evidence of cannibalism.

• Brain Capacity: Estimated around 1,000 cc.

Australopithecus deyiremeda

• When: Approximately 3.5 to 3.3 million years ago.

• Where: Woranso-Mille, Ethiopia (Afar region).

• What: An extinct hominin species whose discovery suggests that multiple hominin lineages co-existed in East Africa during the Middle Pliocene, specifically with A. afarensis. Known from jawbones and teeth, indicating robust chewing adaptations.

• Brain Capacity: Not well-established but

Protoprimates

The earliest ancestors of primates that show some primate characteristics but are not fully primates.

Plesiadapiforms

Early primate-like mammals from the Paleocene period, exhibiting some traits associated with primates.

Adapids

An early group of primates that are considered ancestors of modern lemurs.

Omomyids

Another group of early primates that are thought to be related to modern tarsiers.

Haplorrhines

A suborder of primates that includes monkeys, apes, and humans.

Angiosperms

Flowering plants that appeared during the Cretaceous period, providing new environmental opportunities for mammals.

Fayyum Depression

A significant fossil site in Egypt that contains many primate fossils from the Eocene/Oligocene in swampy forests.

Anthropoids

A group of primates that includes monkeys, apes, and humans, characterized by certain dental and skeletal features.

Miocene Gap

A period of time with sparse fossil records between the Miocene and Pliocene epochs.

Habitual Bipedalism

The condition of consistently walking on two legs, a defining trait of modern humans. Seperates us from an African ape.

Foramen Magnum

The hole at the base of the skull through which the spinal cord passes; in bipeds, it is positioned underneath the skull.

Y-5 Molar

A dental pattern unique to apes, where the lower molars have five cusps arranged in a Y shape.

Cranial Capacity

The volume of the interior of the cranium, an indicator of brain size.

Thermoregulation

The ability of an organism to maintain its body temperature within certain boundaries, even when the surrounding temperature is different.

Carrying Hypothesis

The idea that bipedalism evolved to allow early humans to carry tools and food.

Dental Formula

The number and types of teeth in an animal's mouth, used to identify species and their evolutionary relationships.

Pliocene

The geological epoch that follows the Miocene, featuring further development of hominins.

Postorbital Closure

A bony socket around the eye that is fully enclosed; a trait seen in haplorrhine primates.

Paleoanthropology

The study of ancient hominins and their evolutionary history.

Bipedalism

Locomotion using two legs; a key characteristic that separates humans from other primates.

Plesiadapiforms

Early primate-like mammals that existed during the Paleocene epoch.

Platyrrhines

New World monkeys, characterized by their broad, flat noses and typically prehensile tails.

Proconsulids

An early group of apes that exhibited both monkey-like and ape-like characteristics, lived during the Miocene.

Arboreal quadruped

A type of locomotion used by animals that primarily live in trees and move on all fours.

Diurnal

Active during the daytime; a characteristic of many primate species.

Adaptive advantages of bipedalism

Benefits such as increased visibility for hunting, carrying objects, and energy efficiency.

Sexual dimorphism

Distinct differences in size or appearance between males and females of the same species.

Chimpanzee

One of the closest living relatives of humans, often studied to understand human evolution.

Gymnosperms

Plants with no seeds or flowers that appeared during the Mesozoic era.