Table Of ContentTable of Contents
Timeline: 65 to 1 Million Years BP
CENOZOIC ERA 63 Million Years Ago to the Present
TERTIARY PERIOD 63-2 Million Years Ago
Paleocene (ancient-recent) Epoch 63-58 Million Years Ago
38-23 Million The Oligocene Epoch.
23-5 Million Miocene Epoch.
Pliocene (more-recent) Epoch 6-2 Million years Ago
QUATERNARY PERIOD: 2 MILLION YEARS AGO To The PRESENT
Timeline: 65 to 1 Million Years BP
By Algis Ratnikas
65-1 Million Years Ago
65 Million Placental mammals, 16 or so orders, started to diversify after the
demise of the dinosaurs. (Pac. Disc., summer, '96, p.46)
65 million A 50-foot female T. rex of about this age was discovered on a
Cheyenne River Reservation in South Dakota by Sue Hendrickson in 1990. The
government seized the skeleton in 1992 and in 1997 it was put up for auction by
Sotheby's on behalf of Maurice Williams, a Sioux Indian and owner of the ranch
where it was found. The proceeds will be held in trust by the government.
(SFEC, 9/28/97, p.A13)
c65 Million T. rex "Sue" ate a Duckbill dinosaur and was herself mauled by
another T. rex in South Dakota. She died in a slow moving stream near the shore
of a vast inland sea that bisected North America, and was buried under a
protective layer of sand. (SFC,12/897, p.A4)
65 Million About this time a comet struck the area of the Mexican Yucatan
Peninsula and created a crater, known today as Chicxulub, about 150-180 miles
(200 km) in diameter. The area at this time was covered by ocean. The asteroid
is believed to have been 6-12 miles (10 km) in diameter. Evidence for this was
gathered by Luis Alvarez. In 1997 Walter Alvarez published "T. Rex and the
Crater of Doom," an account of this critical event. The impact was estimated at 5
billion times greater than the atomic bombs of WW II. (SFC, 2/4/97, p.A9)(SFC,
2/18/96, p.A3)(SFEC, 8/17/97, BR p.7)(NH, 9/97, p.85)
65-64.995 Mil A dead zone that lasted about 5,000 years resulted from the
impact of the asteroid that struck Earth was indicated in 1997 seabed drill
sediments. (SFC, 2/18/96, p.A3)
65-55 Million The Paleocene Epoch. (ADH, GHMC,1979, p.24)
65 Million In the early Paleocene a branch that led to living Cetacea (whales)
separated from the Condylartha branch ("knuckle-joints") of land mammals with
hooves that led to Artiodactyla (even-toed hoofed mammals). (LSA, Spg/97,
p.7)
c65 Million In 1998 fossilized fragments of a tiny shrew-like mammal,
Batodonoides, were reported from north-central Wyoming. It weighed as little as
1.3 grams. (SFC, 10/1/98, p.A2)
65-55 Million Road cuts west of Martinez: sandstone and shale. Coast Highway
between San Pedro Point and Devil's Slide: shale and sandstone. Pt. Reyes and
Pt. Lobos: conglomerate, sandstone, shale. (GH-ADH, p.25)
65-21 Million Paleocene to early Miocene. A long period of erosion worked
across the west side of the Great Valley (California). Within the valley early
Tertiary seas fluctuated widely. A seaway, (the Markley Strait) may have
connected the open sea with the Great Valley. It is possible that the Coast Ranges
consisted of a complex of islands at this time. (GH-ADH, p.36)
64-40 Million Fossils from Ellesmere Island in the Canadian Arctic (480 miles
from the North Pole) indicate one time warm temperatures with coal-like fallen
redwoods, large lizards and constrictor snakes, tortoises, alligators, tapirs, and
flying lemurs. (NG, 6/1988, 757)
CENOZOIC ERA 63 Million Years Ago to the Present
(E&IH, 1973, p.42)
TERTIARY PERIOD 63-2 Million Years Ago
(E&IH, 1973, p.42)
Paleocene (ancient-recent) Epoch 63-58 Million Years Ago
(E&IH, 1973, p.42)(LSA, Spg/97, p.6)
60 Million During the last 60 or so million years the break-up of Pangaea
continued with continents drifting northwards and for the most part away from
one another. The shapes of the continents as we know them today began to
clarify and the great Alpine-Himalayan mountains rose from Tethys. In the
Americas the Cordilleran ranges of the west were pushed up and volcanoes
rumbled. For the first time New Zealand can be seen as a separate entity, broken
off as Australia moved northwards. (DD-EVTT, p.204)
60 Million Fleas evolved as highly specialized bloodsucking parasites at least 60
million years ago. (NG, 5/88, p.675)
60 Million The Fossil Butte Member of the Green River Formation in southwest
Wyoming represents the remains of an extinct tropical lake community that
formed about this time and lasted about 20 million years. It included Fossil lake,
Lake Uinta, and Lake Goshuite and covered parts of Wyoming, Utah and
Colorado. (NH, 7/98, p.66)
60 Million The Antilles Islands [of the West Indies] broke off from the
Mesoamerican mainland about 60 million years ago. (Nat. Hist. 3/96, p.15)
60 Million By the middle Paleocene on the branch that led to living Cetacea
there evolved the Mesonychia with blunted, meat-eating dentition and a trotting
gait. They were possibly scavengers and are found on all northern continents. the
transition to whales began when mesonychians went into the water to feed with a
change in dentition. Next to change were the ears and then the reduction of the
sacrum for tail-powered swimming. (LSA, Spg/97, p.7,10)
Eocene (dawn-recent) Epoch 58-36 (56-35) Million Years Ago (E&IH, 1973,
p.42)(LSA, Spg/97, p.6)
55-38 Million The Eocene Epoch (ADH, GHMC,1979, p.24)
Road cuts California south of Antioch reservoir: sandstone and shale. Road cuts
in the vicinity of Woodside: sandstone and shale. Early gold-bearing gravels in
the Sierra Nevada. (GH-ADH, p.25)
Eocene rocks and fossils of Spitsbergen, now at latitude 75 degrees north, tell us
that the climate was warm or sub-tropical, with coal swamps covering hundreds
of square miles of lowland. After the separation of Greenland from Scandinavia
the colder waters of the polar basin would have mingled with the North Atlantic.
The closed North Atlantic Ocean circulation was, by linking with the polar
basin, changed to a more productive system for supporting a large and varied
biota. (DD-EVTT, p.285-286)
Even as early as the Eocene period there were several kinds of whales, including
a slender fearsomely toothed beast (Zeuglodon), as much as 20 meters long.
(DD-EVTT, p.296)
Daniel Axelrod (d.1998), paleobotonist, in 1998 published "Eocene of Thunder
Mountain Flora of Central Idaho." (SFC, 8/7/98, p.D3)
51-50 Million The first whales, the Archeoceti, came from the late-early Eocene.
The earliest of the archeoceti are called pakicetids and are quite similar to
mesonychians. They were found in Pakistan with a land-mammal fauna in
continental deposits. (LSA, Spg/97, p.7)
50 Million The Tethys Sea southern edge was the habitat of Pakicetus inachus, a
small, land mammal (whale ancestor) that walked on four legs and ate fish from
the shallows of the Tethys. This area is presently a rocky, mountainous desert in
Northern Pakistan. Pakicetus had ears apparently adapted for underwater use.
(LSA., S. Pobojewski, p. 36)(PacDis, Winter/'96, p.15)
50 Million Australia's 50 million years of utter isolation has led to the evolution
of plant and animal life that is different than life-forms in relatively nearby parts
of the world. (PacDis, Spring '94, p.3)
50 Million The Fossil Butte Member of the Green River Formation in southwest
Wyoming represents the sedimentary remains of an ancient lake community.
(NH, 7/98, p.66)
50 Million The common ancestor of elephants and sea cows lived about this
time. Researchers in 1999 reported that elephants showed evidence of an aquatic
past and that their trunks were probably used as snorkeling devices. (SFC,
5/11/99, p.A8)
50-49 Million Ambulocetus natans, walking whale that swims, was found in
earliest middle Eocene strata in Pakistan by Hans Thewissen. (LSA, Spg/97,
p.7)
50-42 Million The Green River Formation rocks are remnants of an ancient lake
that covered more than 25,000 square miles of Colorado, Utah and Wyoming.
Lake Uinta, Lake Gosiute, and Fossil Lake were deposited in this period. The
Green River formation is known for deposits such as coal and oil shale, and for
limestone containing abundant fish fossils in mass mortality layers. Fossils
include the herring-like Knightia alta, and less frequently, other fish such as
Priscacara, Mioplosus, Phareodus, and Diplomystus. Rare ancestral manta rays,
palm leaves and birds have also been found. (SFME, 5/7/95, P.5)
49-48 Million Rodhocetus kasrani (whale from Rodho) of the family Porocetidae
had broad frontal bones, widely-spaced eyes, hollow jaws, and massive ear
bones. The four sacral vertebrae are not fused and allowed for tail-powered
swimming. (LSA, Spg/97, p.8)
48-46 Million Later protocetids that include Protocetus atavus, found in Egypt,
and Gaviacetus razai, found in Pakistan, retained single sacral vertebrae that
shows they had highly mobile motive tails. (LSA, Spg/97, p.8)
46 Million Rodhocetus kasrani, a whale that walked on four legs on land, but
swam with the undulating, up-and-down tail motion. Fossil bones discovered in
1992 in Pakistan by U of Mich. paleontologist Philip D. Gingerich and
researchers from the Geological Survey of Pakistan. (LSA., S. Pobojewski, p.
36)
44-40 Million Donald Savage, Russell Ciochon and team of Burmese scientists
in 1978 discovered a primate jaw in Burma dating to this time. (SFC, 4/14/99,
p.C5)
40 Million Basilosaurus (king lizard) isis, a whale species discovered in 1904.
Paleontologists found bones of this creature in the 1830s in Louisiana. Fossils
were found by U of Mich. paleontologist P.D. Gingerich in Egypt in 1989. With
tiny hind limbs too weak to support its body on land, Gingerich believes it spent
its entire life in the ocean. It reached about 40 feet.
(LSA., S. Pobojewski, p. 36)(PacDis, Winter/'96, p.15,16)
40 Million A whale fossil of this age was found in May, 1983, along the
Savannah River in Georgia. (SFC, 10/2/98, p.A10)
40 Million Amber of the Baltic Sea formed about this time. (PacDis, Winter/'97,
p.8)
40 Million A climate change caused the end of the large lake system in
Wyoming, Colorado and Utah. (NH, 7/98, p.68)
40-38Million Dorudon atrox, found in the western desert of Egypt, is a classic
archeocyte. It had a broad skull with multicusped molars, a streamlined body,
forelimbs modified into flippers and a massive tail. It was of the kind first
reported from scattered remains in farmfields of the southeastern US. (LSA,
Spg/97, p.8)
40-5Million The rigid rocks of the Sierra Nevada, thrust upwards during periods
estimated over this time, are riding westward like a surfboard under the impact
of the spreading crust behind it. (SFC, 5/3/96, A-4)
Mid-Cainozoic India encountered the southern margin of Asia, and an open
Tethys no longer existed. The collision of India with Asia squeezed up the
Tethyan sediments into the arcs of the Himalayas. (DD-EVTT, p.288)
A seaway linked the Arctic Ocean and Tethys east of the Urals until Oligocene
time when uplift and the closure of the Tethyan geosyncline put an end to it.
Siberia was from now on no longer separated from Europe and when the climate
began to cool the very large land mass that was now Eurasia felt the extremes
inherent in a continental climate. (DD-EVTT, p.290)
In late Eocene and early Oligocene times the archaic mammals were largely
replaced by the ancestors of our modern mammals. (DD-EVTT, p.296)
38-23 Million The Oligocene Epoch.
(ADH, GHMC,1979, p.24)
Road cuts on Route 9 between Saratoga and Santa Cruz at Riverside Grove:
Sandstone and shale. Road cuts along Route 17 about 5 miles south of Los
Gatos: sandstone and shale. (GH-ADH, p.25)
36-22 (35-29) Million BP Oligocene (little or few-recent) Epoch (E&IH, 1973,
p.42)(LSA, Spg/97, p.6)(LSA, Spg/97, p.8)
35.7 Million Two meteors impacted the Earth. One landed in Siberia and the
other in the Chesapeake Bay. A major extinction also occurred about this time.
[see 35 mil] (NPR, Nature, 7/23/97)(SFEC, 8/22/99, Par p.12)
35 Million In Colorado, a dozen miles from Pike's Peak, a warm temperate
climate supported forests of now-extinct species of white-cedar, pine, palm,
maple, hickory, and members of the beech and elm family. Redwood trees grew
along streams. Animals included the piglike oreodont, rhinoceroslike
brontothere, and an ancestor of the horse. Volcanic eruptions were common.
Lake Florissant formed from a mudflow that dammed a creek flowing through a
valley. It later a dried and provided evidence of 1,100 kinds of insects, 16
vertebrates, and 150 species of plants. (NH, 8/96, p.62)
35 Million The first evidence of human ancestry from Africa dates to about this
time. In 1998 John Reader published "Africa: A Biography of a Continent."
(SFEC, 6/28/98, BR p.12)
35 Million A meteorite impacted at what is now Chesapeake Bay and formed the
largest impact crater in the US. (SFEC, 7/5/98, p.A10)
35 Million The oldest mysticetes, filter-feeding baleen whales with teeth
(aetiocetids) instead of baleen, date to about this time from Antarctica.
35-29Million It was during the Oligocene that the earliest mysticetes (filter
feeders) and odontocetes (echo-locating fish feeders) evolved from archeocetes.
At this time the circulation and the formation of water in the oceans changed
greatly. This altered the distribution of heat on the earth's surface and the global
climate. (LSA, Spg/97, p.8)
33 Million Oligocene. Egypt's Faiyum Depression shows sediments of tropical
rain forests. Aegyptopithecus, a small fruit eating animal of the tropical forest of
North Africa. Dubbed the "dawn-ape" this animal's snout is lemur-like, but the
enclosed eye-sockets and certain dental features, including 32 teeth - typical of
apes and man - make it a likely link with Miocene apes such as Proconsul. (NG,
Nov. 1985, p. 563, 580)
33 Million Five types of mammal fossils have been found in the Badlands of
South Dakota. They are: Archaeotherium (resembling but not related to a pig of
warthog to hippo size), Subhyracodon (an early relative of the rhinoceros),
Mesohippus (a three-toed horse), Leptomeryx (a small deer-like creature), and
an unidentified rodent. (Nat. Hist., 4/96, p.36)
>30 Million The Badlands of South Dakota was for the most part a vast,
featureless floodplain forged by wide, slow-moving rivers from the west. (Nat.
Hist., 4/96, p.31)
>30 million Wonder Cave near San Marcos, Texas, was created on the Balcones
fault line during an earthquake over 30 million years ago. (Sp., 5/96, p.56)
30 Million The hedgehog Proterix loomisi lived in North America and had
developed bony plates in its head for digging and seems to have lacked limbs.
(NH, 7/98, p.56)
30 Million Sperm whale fossils date back to this time. (PacDis, Winter/'96,
p.18)
30 Million By 30 million years ago the subcontinent (India) reached what was
the southern coast of Asia and began to slide beneath it. This southern shore,
once at sea level, took the full force of the collision and is now the Karakorams,
the Black Gravel Range. (NH, 5/96, p.10)
30 Million The Mendocino Triple Junction, a convergence of three tectonic
plates, the Gorda plate, Pacific plate and North American plate, formed in Baha,
California, when an ocean spreading center in the Pacific plate collided with
continent's edge. It now sits close to shore off of Cape Mendocino in Northern
California. (Pac. Disc., summer, '96, p.4)
