HOME TheInfoList.com
Providing Lists of Related Topics to Help You Find Great Stuff
[::MainTopicLength::#1500] [::ListTopicLength::#1500] [::ListLength::#15] [::ListAdRepeat::#3]

Arthropod
Condylipoda Latreille, 1802 An ARTHROPOD (from Greek ἄρθρον _arthron_, "joint" and πούς _pous_, "foot") is an invertebrate animal having an exoskeleton (external skeleton ), a segmented body, and paired jointed appendages . Arthropods form the phylum ARTHROPODA, which includes insects , arachnids , myriapods , and crustaceans . Arthropods are characterized by their jointed limbs and cuticle made of chitin , often mineralised with calcium carbonate . The arthropod body plan consists of segments , each with a pair of appendages . The rigid cuticle inhibits growth, so arthropods replace it periodically by moulting . Their versatility has enabled them to become the most species-rich members of all ecological guilds in most environments. They have over a million described species, making up more than 80% of all described living animal species, some of which, unlike most animals, are very successful in dry environments. Arthropods range in size from the microscopic crustacean _ Stygotantulus _ up to the Japanese spider crab . Arthropods' primary internal cavity is a hemocoel , which accommodates their internal organs , and through which their haemolymph – analogue of blood – circulates; they have open circulatory systems . Like their exteriors, the internal organs of arthropods are generally built of repeated segments
[...More...]

"Arthropod" on:
Wikipedia
Google
Yahoo

Megaannum
A YEAR is the orbital period of the Earth moving in its orbit around the Sun . Due to the Earth's axial tilt , the course of a year sees the passing of the seasons , marked by changes in weather , the hours of daylight , and, consequently, vegetation and soil fertility . In temperate and subpolar regions around the globe, four seasons are generally recognized: _spring _, _summer _, _autumn _ and _winter _. In tropical and subtropical regions several geographical sectors do not present defined seasons; but in the seasonal tropics , the annual _wet _ and _dry_ seasons are recognized and tracked. A calendar year is an approximation of the number of days of the Earth's orbital period as counted in a given calendar . The Gregorian, or modern, calendar , presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars ; _see_ below . For the Gregorian calendar the average length of the calendar year (the mean year) across the complete leap cycle of 400 years is 365.2425 days. The ISO standard ISO 80000-3 , Annex C, supports the symbol "a" (for Latin _annus_) to represent a year of either 365 or 366 days. In English, the abbreviations "y" and "yr" are commonly used
[...More...]

"Megaannum" on:
Wikipedia
Google
Yahoo

picture info

Precambrian
The PRECAMBRIAN (or PRE-CAMBRIAN, sometimes abbreviated PЄ, or CRYPTOZOIC) is the earliest period of Earth\'s history , set before the current Phanerozoic
Phanerozoic
Eon. The Precambrian
Precambrian
is so named because it preceded the Cambrian, the first period of the Phanerozoic
Phanerozoic
eon, which is named after Cambria
Cambria
, the Latinised name for Wales
Wales
, where rocks from this age were first studied. The Precambrian
Precambrian
accounts for 88% of the Earth's geologic time. The Precambrian
Precambrian
(colored green in the timeline figure) is a supereon that is subdivided into three eons (Hadean, Archean, Proterozoic) of the geologic time scale . It spans from the formation of Earth about 4.6 billion years ago (Ga ) to the beginning of the Cambrian
Cambrian
Period, about 541 million years ago (Ma ), when hard-shelled creatures first appeared in abundance
[...More...]

"Precambrian" on:
Wikipedia
Google
Yahoo

Cambrian
The CAMBRIAN Period ( /ˈkæmbriən/ or /ˈkeɪmbriən/ ) was the first geological period of the Paleozoic Era, of the Phanerozoic Eon. The Cambrian lasted 55.6 million years from the end of the preceding Ediacaran Period 541 million years ago (mya) to the beginning of the Ordovician Period 485.4 mya. Its subdivisions, and its base, are somewhat in flux. The period was established (as “Cambrian series”) by Adam Sedgwick , who named it after Cambria , the Latinised form of _Cymru_, the Welsh name for Wales , where Britain's Cambrian rocks are best exposed. The Cambrian is unique in its unusually high proportion of lagerstätte sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biology surpasses that of some later periods. The Cambrian marked a profound change in life on Earth ; prior to the Cambrian, the majority of living organisms on the whole were small, unicellular and simple; the Precambrian _ Charnia _ being exceptional. Complex, multicellular organisms gradually became more common in the millions of years immediately preceding the Cambrian, but it was not until this period that mineralized—hence readily fossilized—organisms became common
[...More...]

"Cambrian" on:
Wikipedia
Google
Yahoo

picture info

Ordovician
The ORDOVICIAN ( /ɔːrdəˈvɪʃən/ ) is a geologic period and system , the second of six periods of the Paleozoic Era . The Ordovician
Ordovician
spans 41.2 million years from the end of the Cambrian Period 485.4 million years ago (Mya) to the start of the Silurian Period 443.8 Mya. The Ordovician, named after the Celtic tribe of the Ordovices , was defined by Charles Lapworth
Charles Lapworth
in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison
Roderick Murchison
, who were placing the same rock beds in northern Wales into the Cambrian
Cambrian
and Silurian periods, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian periods, and placed them in a period of their own. It received international sanction in 1960, when it was adopted as an official period of the Paleozoic Era by the International Geological Congress . Life continued to flourish during the Ordovician
Ordovician
as it did in the earlier Cambrian
Cambrian
period, although the end of the period was marked by the Ordovician– Silurian extinction event . Invertebrates, namely molluscs and arthropods , dominated the oceans
[...More...]

"Ordovician" on:
Wikipedia
Google
Yahoo

Silurian
The SILURIAN is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago (Mya ), to the beginning of the Devonian Period, 419.2 Mya. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by several million years. The base of the Silurian is set at a major Ordovician-Silurian extinction event when 60% of marine species were wiped out. A significant evolutionary milestone during the Silurian was the diversification of jawed and bony fish. Multi-cellular life also began to appear on land in the form of small, bryophyte -like and vascular plants that grew beside lakes, streams, and coastlines, and terrestrial arthropods are also first found on land during the Silurian. However, terrestrial life would not greatly diversify and affect the landscape until the Devonian
[...More...]

"Silurian" on:
Wikipedia
Google
Yahoo

Devonian
The DEVONIAN is a geologic period and system of the Paleozoic , spanning 60 million years from the end of the Silurian , 419.2 million years ago (Mya), to the beginning of the Carboniferous , 358.9 Mya. It is named after Devon , England , where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land , forming extensive forests which covered the continents . By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. Various terrestrial arthropods also became well-established. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the "AGE OF FISH". The first ray-finned and lobe-finned bony fish appeared, while the placodermi began dominating almost every known aquatic environment. The ancestors of all four-limbed vertebrates (tetrapods ) began adapting to walking on land, as their strong pectoral and pelvic fins gradually evolved into legs. In the oceans, primitive sharks became more numerous than in the Silurian and Late Ordovician . The first ammonites , species of molluscs , appeared. Trilobites , the mollusk-like brachiopods and the great coral reefs , were still common
[...More...]

"Devonian" on:
Wikipedia
Google
Yahoo

Carboniferous
The CARBONIFEROUS is a geologic period and system that spans 60 million years from the end of the Devonian Period 358.9 million years ago (Mya ), to the beginning of the Permian Period, 298.9 Mya. The name _Carboniferous_ means "coal-bearing" and derives from the Latin words _carbō_ ("coal ") and _ferō_ ("I bear, I carry"), and was coined by geologists William Conybeare and William Phillips in 1822. Based on a study of the British rock succession, it was the first of the modern 'system' names to be employed, and reflects the fact that many coal beds were formed globally during that time. The Carboniferous is often treated in North America as two geological periods, the earlier Mississippian and the later Pennsylvanian . Terrestrial life was well established by the Carboniferous period. Amphibians were the dominant land vertebrates, of which one branch would eventually evolve into amniotes , the first solely terrestrial vertebrates. Arthropods were also very common, and many (such as _ Meganeura _) were much larger than those of today. Vast swaths of forest covered the land, which would eventually be laid down and become the coal beds characteristic of the Carboniferous stratigraphy evident today
[...More...]

"Carboniferous" on:
Wikipedia
Google
Yahoo

Permian
The PERMIAN is a geologic period and system which spans 46.7 million years from the end of the Carboniferous Period 298.9 million years ago (Mya ), to the beginning of the Triassic Period 252.2 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison , who named it after the city of Perm . The Permian witnessed the diversification of the early amniotes into the ancestral groups of the mammals , turtles , lepidosaurs , and archosaurs . The world at the time was dominated by two continents known as Pangaea and Siberia , surrounded by a global ocean called Panthalassa . The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes , who could better cope with these drier conditions, rose to dominance in place of their amphibian ancestors. The Permian (along with the Paleozoic) ended with the Permian– Triassic extinction event , the largest mass extinction in Earth's history, in which nearly 90% of marine species and 70% of terrestrial species died out. It would take well into the Triassic for life to recover from this catastrophe
[...More...]

"Permian" on:
Wikipedia
Google
Yahoo

Triassic
The TRIASSIC ( /traɪˈæsɪk/ ) is a geologic period and system which spans 50.9 million years from the end of the Permian Period 252.17 million years ago (Mya ), to the beginning of the Jurassic Period 201.3 Mya. The Triassic is the first period of the Mesozoic Era . Both the start and end of the period are marked by major extinction events . The Triassic began in the wake of the Permian– Triassic extinction event , which left the earth's biosphere impoverished; it would take well into the middle of this period for life to recover its former diversity. Therapsids and archosaurs were the chief terrestrial vertebrates during this time. A specialized subgroup of archosaurs , called dinosaurs , first appeared in the Late Triassic but did not become dominant until the succeeding Jurassic Period. The first true mammals , themselves a specialized subgroup of Therapsids , also evolved during this period, as well as the first flying vertebrates, the pterosaurs , who like the dinosaurs were a specialized subgroup of archosaurs . The vast supercontinent of Pangaea existed until the mid-Triassic, after which it began to gradually rift into two separate landmasses, Laurasia to the north and Gondwana to the south. The global climate during the Triassic was mostly hot and dry, with deserts spanning much of Pangaea's interior
[...More...]

"Triassic" on:
Wikipedia
Google
Yahoo

Jurassic
The JURASSIC ( /dʒuːˈræsɪk/ ; from Jura Mountains ) was a geologic period and system that spanned for 56 million years from the end of the Triassic Period 201.3 million years ago (Mya ) to the beginning of the Cretaceous Period 145 Mya. The Jurassic constituted the middle period of the Mesozoic Era , also known as the Age of Reptiles. The start of the period was marked by the major Triassic–Jurassic extinction event . Two other extinction events occurred during the period: the Pliensbachian/ Toarcian event in the Early Jurassic, and the Tithonian event at the end; however, neither event ranks among the "Big Five" mass extinctions. The Jurassic is named after the Jura Mountains within the European Alps , where limestone strata from the period were first identified. By the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses, Laurasia to the north and Gondwana to the south. This created more coastlines and shifted the continental climate from dry to humid, and many of the arid deserts of the Triassic were replaced by lush rainforests. On land, the fauna transitioned from the Triassic fauna, dominated by both dinosauromorph and crocodylomorph archosaurs , to one dominated by dinosaurs alone
[...More...]

"Jurassic" on:
Wikipedia
Google
Yahoo

Cretaceous
The CRETACEOUS ( /krᵻˈteɪʃəs/ , _krə-TAY-shəs_ ) is a geologic period and system that spans 79 million years from the end of the Jurassic Period 145 million years ago (mya ) to the beginning of the Paleogene Period 66 mya. It is the last period of the Mesozoic Era . The Cretaceous Period is usually abbreviated K, for its German translation _Kreide_ (chalk). The Cretaceous was a period with a relatively warm climate , resulting in high eustatic sea levels that created numerous shallow inland seas . These oceans and seas were populated with now-extinct marine reptiles , ammonites and rudists , while dinosaurs continued to dominate on land. During this time, new groups of mammals and birds , as well as flowering plants , appeared. The Cretaceous ended with a large mass extinction , the Cretaceous– Paleogene extinction event , in which many groups, including non-avian dinosaurs, pterosaurs and large marine reptiles died out. The end of the Cretaceous is defined by the abrupt Cretaceous– Paleogene boundary (K–Pg boundary), a geologic signature associated with the mass extinction which lies between the Mesozoic and Cenozoic eras
[...More...]

"Cretaceous" on:
Wikipedia
Google
Yahoo

picture info

Paleogene
The PALEOGENE ( /ˈpæliːədʒiːn/ or /ˈpeɪliːədʒiːn/ ; also spelled PALAEOGENE or PALæOGENE; informally LOWER TERTIARY) is a geologic period and system that spans 43 million years from the end of the Cretaceous
Cretaceous
Period 66 million years ago (Mya ) to the beginning of the Neogene
Neogene
Period 23.03 Mya. It is the beginning of the Cenozoic
Cenozoic
Era of the present PhanerozoicEon. The Paleogene
Paleogene
is most notable for being the time during which mammals diversified from relatively small, simple forms into a large group of diverse animals in the wake of the Cretaceous–Paleogene extinction event
Cretaceous–Paleogene extinction event
that ended the preceding Cretaceous
Cretaceous
Period. This period consists of the Paleocene, Eocene
Eocene
and Oligocene
Oligocene
epochs . The end of the Paleocene(55.5/54.8 Mya) was marked by the Paleocene– Eocene
Eocene
Thermal Maximum , one of the most significant periods of global change during the Cenozoic, which upset oceanic and atmospheric circulation and led to the extinction of numerous deep-sea benthic foraminifera and on land, a major turnover in mammals
[...More...]

"Paleogene" on:
Wikipedia
Google
Yahoo

Neogene
The NEOGENE ( /ˈniːəˌdʒiːn/ ) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period 23.03 million years ago (Mya ) to the beginning of the present Quaternary Period 2.58 Mya. The Neogene is sub-divided into two epochs , the earlier Miocene and the later Pliocene . Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary . During this period, mammals and birds continued to evolve into roughly modern forms, while other groups of life remained relatively unchanged. Early hominids , the ancestors of humans, appeared in Africa near the end of the period. Some continental movement took place, the most significant event being the connection of North and South America at the Isthmus of Panama , late in the Pliocene. This cut off the warm ocean currents from the Pacific to the Atlantic Ocean, leaving only the Gulf Stream to transfer heat to the Arctic Ocean . The global climate cooled considerably over the course of the Neogene, culminating in a series of continental glaciations in the Quaternary Period that follows
[...More...]

"Neogene" on:
Wikipedia
Google
Yahoo

picture info

Taxonomy (biology)
TAXONOMY (from Ancient Greek τάξις _(taxis )_, meaning 'arrangement', and -νομία _(-nomia)_, meaning 'method ') is the science of defining and naming groups of biological organisms on the basis of shared characteristics. Organisms are grouped together into taxa (singular: taxon) and these groups are given a taxonomic rank ; groups of a given rank can be aggregated to form a super group of higher rank, thus creating a taxonomic hierarchy. The principal ranks in modern use are kingdom, phylum, class, order, family, genus and species. The Swedish botanist Carl Linnaeus is regarded as the father of taxonomy, as he developed a system known as Linnaean taxonomy for categorization of organisms and binomial nomenclature for naming organisms. With the advent of such fields of study as phylogenetics , cladistics , and systematics , the Linnaean system has progressed to a system of modern biological classification based on the evolutionary relationships between organisms, both living and extinct
[...More...]

"Taxonomy (biology)" on:
Wikipedia
Google
Yahoo

Animal
ANIMALS are multicellular , eukaryotic organisms of the kingdom ANIMALIA (also called METAZOA). The animal kingdom emerged as a clade within Apoikozoa as the sister group to the choanoflagellates . Animals are motile , meaning they can move spontaneously and independently at some point in their lives. Their body plan eventually becomes fixed as they develop , although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs : they must ingest other organisms or their products for sustenance . Most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion , about 542 million years ago. Animals can be divided broadly into vertebrates and invertebrates . Vertebrates have a backbone or spine (vertebral column ), and amount to less than five percent of all described animal species . They include fish , amphibians , reptiles , birds and mammals . The remaining animals are the invertebrates, which lack a backbone. These include molluscs (clams , oysters , octopuses , squid , snails ); arthropods (millipedes , centipedes , insects , spiders , scorpions , crabs , lobsters , shrimp ); annelids (earthworms , leeches ), nematodes (filarial worms , hookworms ), flatworms (tapeworms , liver flukes ), cnidarians (jellyfish , sea anemones , corals ), ctenophores (comb jellies), and sponges
[...More...]

"Animal" on:
Wikipedia
Google
Yahoo
.