|
Isorophida
Isorophida (the isorophids) is an extinct order of prehistoric echinoderms in the class Edrioasteroidea Edrioasteroidea is an extinct class of echinoderms. The living animal would have resembled a pentamerously symmetrical disc or cushion. They were obligate encrusters and attached themselves to inorganic or biologic hard substrates (frequently har .... References Isorophidaat fossilworks Edrioasteroidea Prehistoric animal orders Echinoderm orders {{paleo-echinoderm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agelacrinitidae
Agelacrinitidae is an extinct family of prehistoric echinoderms in the class Edrioasteroidea Edrioasteroidea is an extinct class of echinoderms. The living animal would have resembled a pentamerously symmetrical disc or cushion. They were obligate encrusters and attached themselves to inorganic or biologic hard substrates (frequently har .... References * Spiraclavus nacoensis, a new species of clavate agelacrinitid edrioasteroid from central Arizona. CD Sumrall, Journal of Paleontology, 1992 Agelacrinitidaeat fossilworks Edrioasteroidea Prehistoric echinoderm families {{paleo-echinoderm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinoderm
An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies". Adult echinoderms are found on the sea bed at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7,000 living species, making it the second-largest grouping of deuterostomes, after the chordates. Echinoderms are the largest entirely marine phylum. The first definitive echinoderms appeared near the start of the Cambrian. The echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the biotic desert of the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs, and limbs; in some cases, they can undergo complete regeneration from a single limb. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edrioasteroidea
Edrioasteroidea is an extinct class of echinoderms. The living animal would have resembled a pentamerously symmetrical disc or cushion. They were obligate encrusters and attached themselves to inorganic or biologic hard substrates (frequently hardgrounds or brachiopods). A 507 million years old species, Totiglobus spencensis, is actually the first known echinoderm adapted to live on a hard surface after the soft microbial mats that covered the seafloor were destroyed in the Cambrian substrate revolution. The oldest undisputed fossils of Edrioasteroidea are known from Cambrian ( Stage 3, about 515-520 Ma ago) of Laurentia and are among the oldest known fossils of echinoderms. Some authors propose that an enigmatic Ediacaran (about 600 Ma) organism '' Arkarua'' is also an edrioasteroid, but this interpretation did not gain wide acceptance. Last edrioasteroids are known from Permian (Late Kungurian, about 270-280 Ma). Anatomy The body plan for this class was simple: a main body ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Animal Orders
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
