Cryptoblastus | |
---|---|
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | † Blastoidea |
Order: | † Spiraculata |
Genus: | † Cryptoblastus Etherridge, Jr. & Carpender, 1886 |
Cryptoblastus is a genus of extinct blastoids, a primitive group of echinoderms related to the modern sea lilies. [1] Fossils are found in sedimentary rocks laid down in the Early Carboniferous period some 360 to 320 million years ago. [2]
Crinoids are marine animals that make up the class Crinoidea, one of the classes of the phylum Echinodermata, which also includes the starfish, brittle stars, sea urchins and sea cucumbers. Those crinoids which, in their adult form, are attached to the sea bottom by a stalk are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, being members of the largest crinoid order, Comatulida.
The Beardmore Glacier in Antarctica is one of the largest valley glaciers in the world, being 200 km (125 mi) long and having a width of 40 km (25 mi). It descends about 2,200 m (7,200 ft) from the Antarctic Plateau to the Ross Ice Shelf and is bordered by the Commonwealth Range of the Queen Maud Mountains on the eastern side and the Queen Alexandra Range of the Central Transantarctic Mountains on the western.
Blastoids are an extinct type of stemmed echinoderm, often referred to as sea buds. They first appear, along with many other echinoderm classes, in the Ordovician period, and reached their greatest diversity in the Mississippian subperiod of the Carboniferous period. However, blastoids may have originated in the Cambrian. Blastoids persisted until their extinction at the end of Permian, about 250 million years ago. Although never as diverse as their contemporary relatives, the crinoids, blastoids are common fossils, especially in many Mississippian-age rocks.
Gerardus Troost was a Dutch-American medical doctor, naturalist, mineralogist, and founding member and first president of the Philadelphia Academy of Natural Sciences.
Gogia is a genus of primitive eocrinoid blastozoan from the early to middle Cambrian.
Crinozoa is a subphylum of mostly sessile echinoderms, of which the crinoids, or sea lilies, are the only extant members. Crinozoans have an extremely extensive fossil history, which may or may not extend into the Precambrian.
Santanachelys gaffneyi is an extinct species of sea turtle. It is the only species in the genus Santanachelys, which itself is a member of the extinct family Protostegidae. The species was first described from a 20-centimeter long fossil specimen unearthed in 1998 from the Santana Formation of eastern Brazil. From the rock layer from which it was excavated, it was determined that the specimen was from the Early Cretaceous period. It is therefore one of the oldest known sea turtles. It was even recorded as the oldest sea turtle in Encyclopædia Britannica, but a new fossil named Desmatochelyspadillai in 2015 is estimated to be as old as 120 million years.
Pentremites is an extinct genus of blastoid echinoderm belonging to the family Pentremitidae.
Deltoblastus is a genus of blastoid echinoderms that lived in the Permian. Its fossils are known from Asia.
The Devonian Jeffersonville Limestone is a mapped bedrock unit in Indiana and Kentucky. It is highly fossiliferous.
Spiraculata is an order of Blastoids. These blastoids are characterized by indirect entrance to the hydrospires through canals by way of pores.
Paleontology in Georgia refers to paleontological research occurring within or conducted by people from the U.S. state of Georgia. During the early part of the Paleozoic, Georgia was largely covered by seawater. Although no major Paleozoic discoveries have been uncovered in Georgia, the local fossil record documents a great diversity of ancient life in the state. Inhabitants of Georgia's early Paleozoic sea included corals, stromatolites, and trilobites. During the Carboniferous local sea levels dropped and a vast complex of richly vegetated delta formed in the state. These swampy deltas were home to early tetrapods which left behind footprints that would later fossilize. Little is known of Triassic Georgia and the Jurassic is absent altogether from the state's rock record. During the Cretaceous, however, southern Georgia was covered by a sea that was home to invertebrates and fishes. On land, the tree Araucaria grew, and dinosaurs inhabited the state. Southern Georgia remained submerged by shallow seawater into the ensuing Paleogene and Neogene periods of the Cenozoic era. These seas were home to small coral reefs and a variety of other marine invertebrates. By the Pleistocene the state was mostly dry land covered in forests and grasslands home to mammoths and giant ground sloths. Local coal mining activity has a history of serendipitous Carboniferous-aged fossil discoveries. Another major event in Georgian paleontology was a 1963 discovery of Pleistocene fossils in Bartow County. Shark teeth are the Georgia state fossil.
Paleontology in Alabama refers to paleontological research occurring within or conducted by people from the U.S. state of Alabama. Pennsylvanian plant fossils are common, especially around coal mines. During the early Paleozoic, Alabama was at least partially covered by a sea that would end up being home to creatures including brachiopods, bryozoans, corals, and graptolites. During the Devonian the local seas deepened and local wildlife became scarce due to their decreasing oxygen levels.
Paleontology in Arkansas refers to paleontological research occurring within or conducted by people from the U.S. state of Arkansas. The fossil record of Arkansas spans from the Ordovician to the Eocene. Nearly all of the state's fossils have come from ancient invertebrate life. During the early Paleozoic, much of Arkansas was covered by seawater. This sea would come to be home to creatures including Archimedes, brachiopods, and conodonts. This sea would begin its withdrawal during the Carboniferous, and by the Permian the entire state was dry land. Terrestrial conditions continued into the Triassic, but during the Jurassic, another sea encroached into the state's southern half. During the Cretaceous the state was still covered by seawater and home to marine invertebrates such as Belemnitella. On land the state was home to long necked sauropod dinosaurs, who left behind footprints and ostrich dinosaurs such as Arkansaurus.
Paleontology in Iowa refers to paleontological research occurring within or conducted by people from the U.S. state of Iowa. The paleozoic fossil record of Iowa spans from the Cambrian to Mississippian. During the early Paleozoic Iowa was covered by a shallow sea that would later be home to creatures like brachiopods, bryozoans, cephalopods, corals, fishes, and trilobites. Later in the Paleozoic, this sea left the state, but a new one covered Iowa during the early Mesozoic. As this sea began to withdraw a new subtropical coastal plain environment which was home to duck-billed dinosaurs spread across the state. Later this plain was submerged by the rise of the Western Interior Seaway, where plesiosaurs lived. The early Cenozoic is missing from the local rock record, but during the Ice Age evidence indicates that glaciers entered the state, which was home to mammoths and mastodons.
Paleontology in Oklahoma refers to paleontological research occurring within or conducted by people from the U.S. state of Oklahoma. Oklahoma has a rich fossil record spanning all three eras of the Phanerozoic Eon. Oklahoma is the best source of Pennsylvanian fossils in the United States due to having an exceptionally complete geologic record of the epoch. From the Cambrian to the Devonian, all of Oklahoma was covered by a sea that would come to be home to creatures like brachiopods, bryozoans, graptolites and trilobites. During the Carboniferous, an expanse of coastal deltaic swamps formed in areas of the state where early tetrapods would leave behind footprints that would later fossilize. The sea withdrew altogether during the Permian period. Oklahoma was home a variety of insects as well as early amphibians and reptiles. Oklahoma stayed dry for most of the Mesozoic. During the Late Triassic, carnivorous dinosaurs left behind footprints that would later fossilize. During the Cretaceous, however, the state was mostly covered by the Western Interior Seaway, which was home to huge ammonites and other marine invertebrates. During the Cenozoic, Oklahoma became home to creatures like bison, camels, creodonts, and horses. During the Ice Age, the state was home to mammoths and mastodons. Local Native Americans are known to have used fossils for medicinal purposes. The Jurassic dinosaur Saurophaganax maximus is the Oklahoma state fossil.
The Cuyahoga Formation is a geologic formation in Ohio. The age of the formation is difficult to determine, because of a lack of diagnostic fossils. Roughly, the formation dates from the Late Kinderhookian to the Middle Osagean. Eight members are recognized, among them the Orangeville Shale, Sharpsville Sandstone, and Meadville Shale.
The Milwaukee Formation is a fossil-bearing geological formation of Middle Devonian age in Milwaukee County, Wisconsin. It stands out for the exceptional diversity of its fossil biota. Included are many kinds of marine protists, invertebrates, and fishes, as well as early trees and giant fungi.
The St. Joe Formation or St. Joe Limestone Member is a geologic formation or member in northern Arkansas, southern Missouri and northeastern Oklahoma. It preserves fossils of the Mississippian subperiod including crinoids, brachiopods, bryozoa, conodonts, blastoids, ostracods and rugose coral.
The Fig Tree Formation, also called Fig Tree Group, is a stromatolite-containing geological formation in South Africa. The rock contains fossils of microscopic life forms of about 3.26 billion years old. Identified organisms include the bacterium Eobacterium isolatus and the algae-like Archaeosphaeroides barbertonensis. The fossils in the Fig Tree Formation are considered some of the oldest known organisms on Earth, and provide evidence that life may have existed much earlier than previously thought. The formation is composed of shales, turbiditic greywackes, volcaniclastic sandstones, chert, turbiditic siltstone, conglomerate, breccias, mudstones, and iron-rich shales.