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The Paleogene Portal

Introduction

The Paleogene Period (IPA: /ˈpeɪli.ədʒiːn, -li.oʊ-, ˈpæli-/ PAY-lee-ə-jeen, -⁠lee-oh-, PAL-ee-; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period 66 million years ago (Mya) to the beginning of the Neogene Period 23.03 Mya. It is the first part of the Cenozoic Era of the present Phanerozoic Eon. The earlier term Tertiary Period was used to define the time now covered by the Paleogene Period and subsequent Neogene Period; despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use. Paleogene is often abbreviated "Pg", although the United States Geological Survey uses the abbreviation "Pe" for the Paleogene on the Survey's geologic maps.

During the Paleogene period, mammals continued to diversify from relatively small, simple forms into a large group of diverse animals in the wake of the Cretaceous–Paleogene extinction event that ended the preceding Cretaceous Period. (Full article...)

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Selected article on the Paleogene world and its legacies

Crustaceans (Crustacea) form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 67,000 described species range in size from Stygotantulus stocki at 0.1 mm (0.004 in), to the Japanese spider crabwith a leg span of up to 3.8 m (12.5 ft) and a mass of 20 kg (44 lb). Like other arthropods, crustaceans have an exoskeleton, which they moult to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates, by the possession of biramous (two-parted) limbs, and by the nauplius form of the larvae.

Most crustaceans are free-living aquatic animals, but some are terrestrial (e.g. woodlice), some are parasitic (e.g. Rhizocephala, fish lice, tongue worms) and some are sessile (e.g. barnacles). The group has an extensive fossil record, reaching back to the Cambrian, and includes living fossils such as Triops cancriformis, which has existed apparently unchanged since the Triassic period. More than 10 million tons of crustaceans are produced by fishery or farming for human consumption, the majority of it being shrimp and prawns. Krill and copepods are not as widely fished, but may be the animals with the greatest biomass on the planet, and form a vital part of the food chain. The scientific study of crustaceans is known as carcinology, and a scientist who works in carcinology is a carcinologist. (see more...)

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Did you know?

... that the extinct Eocene parasitic wasp Brevivulva electroma (pictured) was named from the Greek words meaning "short amber wrapper"?
... that only one side of the extinct parasitic wasp Neanaperiallus is visible in its sole fossilized specimen?
... that, when described, the brown lacewing species Wesmaelius mathewesi was the most ancient member of its subfamily?
... that the primary leaf veins for the extinct plant Trochodendron nastae are palmate rather than being pinnate like those in the living Trochodendron aralioides?
... that the extinct sawfly Pseudosiobla cambelli is one of three species of Pseudosiobla known from the fossil record?

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Fossil of Saniwa ensidens in the Field Museum of Natural History.
Photo credit: User:Smokeybjb

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Selected article on the Paleogene in human science, culture and economics

The Palanga Amber Museum, near the Baltic Sea in Palanga, Lithuania, is a branch of the Lithuanian Art Museum. It is housed in the restored 19th-century Tiškevičiai Palace and is surrounded by the Palanga Botanical Garden. The museum's collection of amber comprises about 28,000 pieces, of which about 15,000 contain inclusions of insects, spiders, or plants. About 4,500 pieces of amber are exhibited; many of these are items of artwork and jewelry.

The first floor is dedicated to displays that illustrate the formation and composition of amber. Amber in the area arose from deltaic deposits of rivers flowing from Fennoscandia in the Eocene Period, about 40 to 45 million years ago. The processes via which resin is changed into amber by microorganisms, oxidation, and polymerization are illustrated. Samples of microdrops and microicicles (i.e. "amber within amber") are among the displayed items. The museum holds Europe's third largest amber specimen, the "Sun Stone", of size 210x190x150 mm and weighing 3,526 grams, which has been stolen twice. Amber from other areas of the world is also part of the collection.(see more...)

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