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A. Sediba
''Australopithecus sediba'' is an extinct species of australopithecine recovered from Malapa Cave, Cradle of Humankind, South Africa. It is known from a partial juvenile skeleton, the holotype MH1, and a partial adult female skeleton, the paratype MH2. They date to about 1.98 million years ago in the Early Pleistocene, and coexisted with '' Paranthropus robustus'' and ''Homo ergaster'' / '' Homo erectus''. Malapa is interpreted as having been a natural death trap, the base of a long vertical shaft which creatures could accidentally fall into. ''A. sediba'' was initially described as being a potential human ancestor, and perhaps the progenitor of ''Homo'', but this is contested and it could also represent a late-surviving population or sister species of '' A. africanus'' which had earlier inhabited the area. MH1 has a brain volume of about 420–440 cc, similar to other australopithecines. The face of MH1 is strikingly similar to ''Homo'' instead of other australopithecines, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Pleistocene
The Early Pleistocene is an unofficial sub-epoch in the international geologic timescale in chronostratigraphy, being the earliest division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently estimated to span the time between 2.580 ± 0.005 Ma (million years ago) and 0.773 ± 0.005 Ma. The term Early Pleistocene applies to both the Gelasian Age (to 1.800 ± 0.005 Ma) and the Calabrian Age. While the Gelasian and the Calabrian have officially been defined by the International Union of Geological Sciences (IUGS) to effectively constitute the Early Pleistocene, the succeeding Chibanian and Tarantian ages have yet to be ratified. These proposed ages are unofficially termed the Middle Pleistocene and Late Pleistocene The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth div ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arboreal
Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose numerous mechanical challenges to animals moving through them and lead to a variety of anatomical, behavioral and ecological consequences as well as variations throughout different species.Cartmill, M. (1985). Climbing. In ''Functional Vertebrate Morphology'', eds. M. Hildebrand D. M. Bramble K. F. Liem and D. B. Wake, pp. 73–88. Cambridge: Belknap Press. Furthermore, many of these same principles may be applied to climbing without trees, such as on rock piles or mountains. Some animals are exclusively arboreal in habitat, such as the tree snail. Biomechanics Arboreal habitats pose numerous mechanical challenges to animals moving in them, which have been solved in diverse ways. These challenges include moving on n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canine Tooth
In mammalian oral anatomy, the canine teeth, also called cuspids, dog teeth, or (in the context of the upper jaw) fangs, eye teeth, vampire teeth, or vampire fangs, are the relatively long, pointed teeth. They can appear more flattened however, causing them to resemble incisors and leading them to be called ''incisiform''. They developed and are used primarily for firmly holding food in order to tear it apart, and occasionally as weapons. They are often the largest teeth in a mammal's mouth. Individuals of most species that develop them normally have four, two in the upper jaw and two in the lower, separated within each jaw by incisors; humans and dogs are examples. In most species, canines are the anterior-most teeth in the maxillary bone. The four canines in humans are the two maxillary canines and the two mandibular canines. Details There are generally four canine teeth: two in the upper (maxillary) and two in the lower (mandibular) arch. A canine is placed laterally to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebral Column
The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column is the defining characteristic of a vertebrate in which the notochord (a flexible rod of uniform composition) found in all chordata, chordates has been replaced by a segmented series of bone: vertebrae separated by intervertebral discs. Individual vertebrae are named according to their region and position, and can be used as anatomical landmarks in order to guide procedures such as Lumbar puncture, lumbar punctures. The vertebral column houses the spinal canal, a cavity that encloses and protects the spinal cord. There are about 50,000 species of animals that have a vertebral column. The human vertebral column is one of the most-studied examples. Many different diseases in humans can affect the spine, with spina bifida and scoliosis being recognisable examples. The general structure of human vertebrae is fairly typical of that found in mammals, reptiles, and birds. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribcage
The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels. The sternum, together known as the thoracic cage, is a semi-rigid bony and cartilaginous structure which surrounds the thoracic cavity and supports the shoulder girdle to form the core part of the human skeleton. A typical human thoracic cage consists of 12 pairs of ribs and the adjoining costal cartilages, the sternum (along with the manubrium and xiphoid process), and the 12 thoracic vertebrae articulating with the ribs. Together with the skin and associated fascia and muscles, the thoracic cage makes up the thoracic wall and provides attachments for extrinsic skeletal muscles of the neck, upper limbs, upper abdomen and back. The rib cage intrinsically holds the muscles of respiration ( diaphragm, intercostal muscles, etc.) that are crucial for active inhalation and forced exhalation, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clavicle
The clavicle, or collarbone, is a slender, S-shaped long bone approximately 6 inches (15 cm) long that serves as a strut between the shoulder blade and the sternum (breastbone). There are two clavicles, one on the left and one on the right. The clavicle is the only long bone in the body that lies horizontally. Together with the shoulder blade, it makes up the shoulder girdle. It is a palpable bone and, in people who have less fat in this region, the location of the bone is clearly visible. It receives its name from the Latin ''clavicula'' ("little key"), because the bone rotates along its axis like a key when the shoulder is abducted. The clavicle is the most commonly fractured bone. It can easily be fractured by impacts to the shoulder from the force of falling on outstretched arms or by a direct hit. Structure The collarbone is a thin doubly curved long bone that connects the arm to the trunk of the body. Located directly above the first rib, it acts as a strut to k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matthew Berger
Lee Rogers Berger (born December 22, 1965) is an American-born South African paleoanthropologist and National Geographic Explorer-in-Residence. He is best known for his discovery of the ''Australopithecus sediba'' type site, Malapa; his leadership of Rising Star Expedition in the excavation of ''Homo naledi'' at Rising Star Cave; and the Taung Bird of Prey Hypothesis. Berger is known not only for his discoveries, but also for his unusually public persona in paleoanthropology, and for making his most notable discoveries open-access projects. He gives hundreds of talks per year, and has had a close relationship with National Geographic for many years, appearing in several of their shows and documentaries. Early life and education Berger was born in Shawnee Mission, Kansas in 1965, but was raised outside of Sylvania, Georgia in the United States. As a youth, Berger was active in the Boy Scouts, Future Farmers of America, and president of Georgia 4-H. In 1984, Berger was named G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generalist And Specialist Species
A generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources (for example, a heterotroph with a varied diet). A specialist species can thrive only in a narrow range of environmental conditions or has a limited diet. Most organisms do not all fit neatly into either group, however. Some species are highly specialized (the most extreme case being monophagous, eating one specific type of food), others less so, and some can tolerate many different environments. In other words, there is a continuum from highly specialized to broadly generalist species. Description Omnivores are usually generalists. Herbivores are often specialists, but those that eat a variety of plants may be considered generalists. A well-known example of a specialist animal is the monophagous koala, which subsists almost entirely on eucalyptus leaves. The raccoon is a generalist, because it has a natural range that includes most of North ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chimpanzee
The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative the bonobo was more commonly known as the pygmy chimpanzee, this species was often called the common chimpanzee or the robust chimpanzee. The chimpanzee and the bonobo are the only species in the genus ''Pan''. Evidence from fossils and DNA sequencing shows that ''Pan'' is a sister taxon to the human lineage and is humans' closest living relative. The chimpanzee is covered in coarse black hair, but has a bare face, fingers, toes, palms of the hands, and soles of the feet. It is larger and more robust than the bonobo, weighing for males and for females and standing . The chimpanzee lives in groups that range in size from 15 to 150 members, although individuals travel and forage in much smaller groups during the day. The species lives in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C4 Carbon Fixation
carbon fixation or the Hatch–Slack pathway is one of three known photosynthetic processes of carbon fixation in plants. It owes the names to the 1960's discovery by Marshall Davidson Hatch and Charles Roger Slack that some plants, when supplied with 14, incorporate the 14C label into four-carbon molecules first. fixation is an addition to the ancestral and more common carbon fixation. The main carboxylating enzyme in photosynthesis is called RuBisCO, which catalyses two distinct reactions using either (carboxylation) or oxygen (oxygenation) as a substrate. The latter process, oxygenation, gives rise to the wasteful process of photorespiration. photosynthesis reduces photorespiration by concentrating around RuBisCO. To ensure that RuBisCO works in an environment where there is a lot of carbon dioxide and very little oxygen, leaves generally differentiate two partially isolated compartments called mesophyll cells and bundle-sheath cells. is initially fixed in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hominin
The Hominini form a taxonomic tribe of the subfamily Homininae ("hominines"). Hominini includes the extant genera ''Homo'' (humans) and '' Pan'' (chimpanzees and bonobos) and in standard usage excludes the genus ''Gorilla'' (gorillas). The term was originally introduced by Camille Arambourg (1948). Arambourg combined the categories of ''Hominina'' and ''Simiina'' due to Gray (1825) into his new subtribe. Traditionally, chimpanzees, gorillas and orangutans were grouped together as pongids. Since Gray's classification, evidence has accumulated from genetic phylogeny confirming that humans, chimpanzees, and gorillas are more closely related to each other than to the orangutan. The former pongids were reassigned to the subfamily Hominidae ("great apes"), which already included humans, but the details of this reassignment remain contested; within Hominini, not every source excludes gorillas, and not every source includes chimpanzees. Humans are the only extant species in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedge
The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus ''Carex'' with over 2,000 species. These species are widely distributed, with the centers of diversity for the group occurring in tropical Asia and tropical South America. While sedges may be found growing in almost all environments, many are associated with wetlands, or with poor soils. Ecological communities dominated by sedges are known as sedgelands or sedge meadows. Some species superficially resemble the closely related rushes and the more distantly related grasses. Features distinguishing members of the sedge family from grasses or rushes are stems with triangular cross-sections (with occasional exceptions, a notable example being the tule which has a round cross-section) and leaves that are spirally arranged in three ranks. In comparison, g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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