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Proconsul, in zoology

(Encyclopedia)Proconsul, extinct group of apes. Proconsul fossils have been discovered in E Africa. It had a mixture of ape and Old World monkey characteristics, and lived from 23 to 25 million years ago. ...

period, in geologic time

(Encyclopedia)period, unit of time on the geologic timescale. Periods are shorter than an era and longer than an epoch. Periods are of variable length, generally lasting tens of millions of years, with characterist...

Cambrian period

(Encyclopedia)Cambrian period [Lat. Cambria=Wales], first period of the Paleozoic geologic era (see Geologic Timescale, tablegeologic timescale, table) extending from approximately 570 to 505 million years ago. It ...

badlands

(Encyclopedia)badlands, area of severe erosion, usually found in semiarid climates and characterized by countless gullies, steep ridges, and sparse vegetation. Badland topography is formed on poorly cemented sedime...

Lepidodendron and Sigillaria

(Encyclopedia)Lepidodendron sĭjĭlârˈēə [key], two principal genera of an extinct group of primitive vascular trees. They dominated the forests of the early Carboniferous period until the ferns gained ascendan...

Pauncefote of Preston, Julian Pauncefote, 1st Baron

(Encyclopedia)Pauncefote of Preston, Julian Pauncefote, 1st Baron pônsˈfo͝ot [key], 1828–1902, British diplomat. He served in various positions in the colonies before becoming (1882) permanent undersecretary f...

Pitch Lake

(Encyclopedia)Pitch Lake, pool of pitch (asphalt), c.114 acres (46 hectares), SW Trinidad island, Trinidad and Tobago, near La Brea. The lake is believed to be formed and supplied by the seepage of natural pitch, a...

Oreopithecus

(Encyclopedia)Oreopithecus ôrˌēōpĭthˈəkəs, –pĭthēˈkəs [key], extinct genus of apes whose fossils have been found in E Africa and Italy. It is best known through specimens preserved in coal deposits. I...

stromatolite

(Encyclopedia)stromatolite, layered structures produced by the binding together of sediments by a thin layer of cyanobacteria. The layers, which are deposited very slowly, gradually produce rounded or hummocklike f...

La Brea

(Encyclopedia)La Brea lə brāˈə [key], area, S Calif., formerly in Rancho La Brea. The La Brea asphalt pits, which yielded prehistoric animal and plant remains, are in Hancock Park, Los Angeles. The first fossil...