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52-426: Los Angeles Museum may refer to: Natural History Museum of Los Angeles County , established 1913 Los Angeles County Museum of Art , forked from the previous in 1961 Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Los Angeles Museum . If an internal link led you here, you may wish to change

104-405: A Becoming Los Angeles that showcases Los Angeles history through the years, divided up into before 1929 and after 1929. Another example would be the current exhibit titled L.A. Underwater which exhibits almost 40 fossils from the prehistoric time, when the land where L.A. now is, was underwater. The museum also hosts a butterfly pavilion outside every spring and summer and a spider pavilion on

156-405: A blunt snout and reduced dentition rely on suction feeding . Though carnivorous, they house gut flora similar to that of terrestrial herbivores, probably a remnant of their herbivorous ancestry. Baleen whales use their baleen plates to sieve plankton, among others, out of the water; there are two types of methods: lunge-feeding and gulp-feeding. Lunge-feeders expand the volume of their jaw to

208-525: A café, and a plaza. The museum maintains research and collections in the following fields: The museum has three floors of permanent exhibits. Among the most popular museum displays are those devoted to animal habitats , dinosaurs , pre-Columbian cultures, The Ralph M. Parsons Discovery Center and Insect Zoo, and the new Nature Lab, which explores urban wildlife in Southern California. The museum's collections are strong in many fields, but

260-627: A divergence of the Monachinae (monk seals) and Phocinae lineages 22 mya. Fossil evidence indicates the sea otter ( Enhydra ) lineage became isolated in the North Pacific approximately two mya, giving rise to the now-extinct † Enhydra macrodonta and the modern sea otter, Enhydra lutris . The sea otter evolved initially in northern Hokkaidō and Russia, and then spread east to the Aleutian Islands , mainland Alaska , and down

312-471: A few are specialists. They typically hunt non-schooling fish, slow-moving or immobile invertebrates or endothermic prey when in groups. Solitary foraging species usually exploit coastal waters, bays and rivers. When large schools of fish or squid are available, pinnipeds hunt cooperatively in large groups, locating and herding their prey. Some species, such as California and South American sea lions, may forage with cetaceans and sea birds. The polar bear

364-501: A few eat other mammals. While the number of marine mammals is small compared to those found on land, their roles in various ecosystems are large, especially concerning the maintenance of marine ecosystems, through processes including the regulation of prey populations. This role in maintaining ecosystems makes them of particular concern as 23% of marine mammal species are currently threatened. Marine mammals were first hunted by aboriginal peoples for food and other resources. Many were also

416-698: A number of features for efficient locomotion such as torpedo-shaped bodies to reduce drag; modified limbs for propulsion and steering ; tail flukes and dorsal fins for propulsion and balance. Marine mammals are adept at thermoregulation using dense fur or blubber , circulatory adjustments ( counter-current heat exchange ); and reduced appendages, and large size to prevent heat loss. Marine mammals are able to dive for long periods. Both pinnipeds and cetaceans have large and complex blood vessel systems pushing large volumes of blood rich in myoglobin and hemoglobin , which serve to store greater quantities of oxygen . Other important reservoirs include muscles and

468-438: A number of terrestrial habitats, both continental and island. In temperate and tropical areas, they haul-out on to sandy and pebble beaches, rocky shores , shoals , mud flats , tide pools and in sea caves . Some species also rest on man-made structures, like piers , jetties , buoys and oil platforms . Seals may move further inland and rest in sand dunes or vegetation, and may even climb cliffs. Most cetaceans live in

520-629: A period of glaciation in the Pleistocene or from the eastern part of Siberia , (from Kamchatka and the Kolym Peninsula). The oldest known polar bear fossil is a 130,000-to-110,000-year-old jaw bone, found on Prince Charles Foreland in 2004. The mitochondrial DNA (mtDNA) of the polar bear diverged from the brown bear roughly 150,000 years ago. Further, some clades of brown bear, as assessed by their mtDNA, are more closely related to polar bears than to other brown bears, meaning that

572-442: A seal to appear. When the seal exhales, the bear smells its breath, reaches into the hole with a forepaw, and drags it out onto the ice. The polar bear also hunts by stalking seals resting on the ice. Upon spotting a seal, it walks to within 100 yards (90 m), and then crouches. If the seal does not notice, the bear creeps to within 30 to 40 feet (9 to 10 m) of the seal and then suddenly rushes to attack. A third hunting method

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624-1166: A stained glass dome, the room is also the home of the very first piece of public art funded by Los Angeles County , a Beaux-Arts statue by Julia Bracken Wendt entitled Three Muses , or History, Science and Art . This hall is among the most distinctive locales in Los Angeles and has often been used as a filming location. 34°01′01″N 118°17′20″W  /  34.016989°N 118.288781°W  / 34.016989; -118.288781 Marine mammal Marine mammals are mammals that rely on marine (saltwater) ecosystems for their existence. They include animals such as cetaceans ( whales , dolphins and porpoises ), pinnipeds ( seals , sea lions and walruses ), sirenians ( manatees and dugongs ), sea otters and polar bears . They are an informal group, unified only by their reliance on marine environments for feeding and survival. Marine mammal adaptation to an aquatic lifestyle varies considerably between species. Both cetaceans and sirenians are fully aquatic and therefore are obligate water dwellers. Pinnipeds are semiaquatic; they spend

676-430: A volume bigger than the original volume of the whale itself by inflating their mouth. This causes grooves on their throat to expand, increasing the amount of water the mouth can store. They ram a baitball at high speeds in order to feed, but this is only energy-effective when used against a large baitball. Gulp-feeders swim with an open mouth, filling it with water and prey. Prey must occur in sufficient numbers to trigger

728-920: Is associated with two other museums in Greater Los Angeles : the Page Museum at the La Brea Tar Pits in Hancock Park and the William S. Hart Ranch and Museum in Newhall . The three museums work together to achieve their common mission: "to inspire wonder, discovery, and responsibility for our natural and cultural worlds." NHM opened in Exposition Park , Los Angeles , California , United States in 1913 as The Museum of History, Science, and Art. The moving force behind it

780-563: Is held in The Seaver Center for Western History Research. The museum hosts regular special exhibitions which augment its collections and advance its mission. Recent special exhibits have included Mummies and Pterosaurs , both in 2016. The museum has also recently hosted exhibits that incorporate pop culture, such as an exhibit promoting House of the Dragon in 2022. There have also been Los Angeles themed special exhibits such as

832-530: Is herding, where a pod squeezes a school of fish into a small volume, known as a bait ball . Individual members then take turns plowing through the ball, feeding on the stunned fish. Coralling is a method where dolphins chase fish into shallow water to catch them more easily. Killer whales and bottlenose dolphins have also been known to drive their prey onto a beach to feed on it. Killer whales have been known to paralyze great white sharks and other sharks and rays by flipping them upside down. Other whales with

884-418: Is scarce. West Indian manatees eat up to 60 different species of plants, as well as fish and small invertebrates to a lesser extent. Sea otters are a classic example of a keystone species; their presence affects the ecosystem more profoundly than their size and numbers would suggest. They keep the population of certain benthic (sea floor) herbivores, particularly sea urchins , in check. Sea urchins graze on

936-408: Is the development of echolocation in whales and dolphins. Toothed whales emit a focused beam of high-frequency clicks in the direction that their head is pointing. Sounds are generated by passing air from the bony nares through the phonic lips. These sounds are reflected by the dense concave bone of the cranium and an air sac at its base. The focused beam is modulated by a large fatty organ known as

988-428: Is the most carnivorous species of bear, and its diet primarily consists of ringed ( Pusa hispida ) and bearded ( Erignathus barbatus ) seals. Polar bears hunt primarily at the interface between ice, water, and air; they only rarely catch seals on land or in open water. The polar bear's most common hunting method is still-hunting: The bear locates a seal breathing hole using its sense of smell, and crouches nearby for

1040-720: Is the only marine mammal that catches fish with its forepaws rather than with its teeth. Under each foreleg, sea otters have a loose pouch of skin that extends across the chest which they use to store collected food to bring to the surface. This pouch also holds a rock that is used to break open shellfish and clams, an example of tool use . The sea otters eat while floating on their backs, using their forepaws to tear food apart and bring to their mouths. Marine otters mainly feed on crustaceans and fish. Pinnipeds mostly feed on fish and cephalopods , followed by crustaceans and bivalves , and then zooplankton and warm-blooded prey (like sea birds ). Most species are generalist feeders, but

1092-437: Is to raid the birth lairs that female seals create in the snow. They may also feed on fish. Sirenians are referred to as "sea cows" because their diet consists mainly of seagrass. When eating, they ingest the whole plant, including the roots, although when this is impossible they feed on just the leaves. A wide variety of seagrass has been found in dugong stomach contents, and evidence exists they will eat algae when seagrass

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1144-572: The Eocene . Their evolutionary link to terrestrial mammals was unknown until the 2007 discovery of † Puijila darwini in early Miocene deposits in Nunavut , Canada. Like a modern otter, † Puijila had a long tail, short limbs and webbed feet instead of flippers. The lineages of Otariidae (eared seals) and Odobenidae (walrus) split almost 28 mya. Phocids (earless seals) are known to have existed for at least 15 mya, and molecular evidence supports

1196-486: The Indian Ocean . The variation observed in range size is a result of the different ecological requirements of each species and their ability to cope with a broad range of environmental conditions. The high degree of overlap between marine mammal species richness and areas of human impact on the environment is of concern. Most marine mammals, such as seals and sea otters, inhabit the coast. Seals, however, also use

1248-551: The North Atlantic right whale , are critically endangered . Other than being hunted, marine mammals can be killed as bycatch from fisheries, where for example they can become entangled in nets and drown or starve. Increased ocean traffic causes collisions between fast ocean vessels and large marine mammals. Habitat degradation also threatens marine mammals and their ability to find and catch food. Noise pollution , for example, may adversely affect echolocating mammals, and

1300-551: The North Ronaldsay sheep ( Ovis aries ) which normally eats seaweed outside the lambing season, the Eurasian otter ( Lutra lutra ) which is usually found in freshwater but can be found along coastal Scotland , and others. Marine mammals form a diverse group of 129 species that rely on the ocean for their existence. They are an informal group unified only by their reliance on marine environments for feeding. Despite

1352-574: The Old World (such as cetaceans ). The first known quadrupedal sirenian was † Pezosiren from the early middle Eocene. The earliest known sea cows, of the families † Prorastomidae and † Protosirenidae , were both confined to the Eocene, and were pig-sized, four-legged, amphibious creatures. The first members of Dugongidae appeared by the middle Eocene. At this point, sea cows were fully aquatic. Pinnipeds split from other caniforms 50 mya during

1404-522: The hippopotamuses . Sirenians, the sea cows, became aquatic around 40 million years ago. The first appearance of sirenians in the fossil record was during the early Eocene, and by the late Eocene, sirenians had significantly diversified. Inhabitants of rivers, estuaries, and nearshore marine waters, they were able to spread rapidly. The most primitive sirenian, † Prorastomus , was found in Jamaica, unlike other marine mammals which originated from

1456-643: The spleen which all have the capacity to hold a high concentration of oxygen. They are also capable of bradycardia (reduced heart rate), and vasoconstriction (shunting most of the oxygen to vital organs such as the brain and heart) to allow extended diving times and cope with oxygen deprivation. If oxygen is depleted ( hypoxia ), marine mammals can access substantial reservoirs of glycogen that support anaerobic glycolysis . Sound travels differently through water, and therefore marine mammals have developed adaptations to ensure effective communication, prey capture, and predator detection. The most notable adaptation

1508-430: The 'melon'. This acts like an acoustic lens because it is composed of lipids of differing densities. Marine mammals have evolved a wide variety of features for feeding, which are mainly seen in their dentition. For example, the cheek teeth of pinnipeds and odontocetes are specifically adapted to capture fish and squid. In contrast, baleen whales have evolved baleen plates to filter feed plankton and small fish from

1560-742: The Museum of History and Science was renamed The Los Angeles County Museum of Natural History. Eventually, the museum renamed itself again, becoming The Natural History Museum of Los Angeles County. In 2003, the museum began a campaign to transform its exhibits and visitor experience. The museum reopened its seismically retrofitted renovated 1913 rotunda, along with the new "Age of Mammals" exhibition in 2010. Its Dinosaur Hall opened in July 2011. A new Los Angeles history exhibition, "Becoming Los Angeles", opened in 2013. The outdoor Nature Gardens and Nature Lab, which explore L.A. wildlife, also opened in 2013. In 2024,

1612-528: The North American coast. In comparison to cetaceans, sirenians, and pinnipeds, which entered the water approximately 50, 40, and 20 mya, respectively, the sea otter is a relative newcomer to marine life. In some respects though, the sea otter is more fully adapted to water than pinnipeds, which must haul out on land or ice to give birth. Polar bears are thought to have diverged from a population of brown bears , Ursus arctos , that became isolated during

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1664-461: The cetaceans genetically and morphologically fall firmly within the Artiodactyla (even-toed ungulates). The term "Cetartiodactyla" reflects the idea that whales evolved within the ungulates. The term was coined by merging the name for the two orders, Cetacea and Artiodactyla, into a single word. Under this definition, the closest living land relative of the whales and dolphins is thought to be

1716-521: The diversity in anatomy seen between groups, improved foraging efficiency has been the main driver in their evolution . The level of dependence on the marine environment varies considerably with species. For example, dolphins and whales are completely dependent on the marine environment for all stages of their life; seals feed in the ocean but breed on land; and polar bears must feed on land. The cetaceans became aquatic around 50 million years ago (mya). Based on molecular and morphological research,

1768-812: The floor or to stay submerged. Surface-living animals (such as sea otters) need the opposite, and free-swimming animals living in open waters (such as dolphins) need to be neutrally buoyant in order to be able to swim up and down the water column. Typically, thick and dense bone is found in bottom feeders and low bone density is associated with mammals living in deep water. Some marine mammals, such as polar bears and otters, have retained four weight-bearing limbs and can walk on land like fully terrestrial animals. All cetaceans are carnivorous and predatory . Toothed whales mostly feed on fish and cephalopods , followed by crustaceans and bivalves . Some may forage with other kinds of animals, such as other species of whales or certain species of pinnipeds . One common feeding method

1820-454: The globe, but their distribution is patchy and coincides with the productivity of the oceans. Species richness peaks at around 40° latitude, both north and south. This corresponds to the highest levels of primary production around North and South America , Africa , Asia and Australia . Total species range is highly variable for marine mammal species. On average most marine mammals have ranges which are equivalent or smaller than one-fifth of

1872-529: The ice further north that remains frozen year-round. Seals may also migrate to other environmental changes, such as El Niño , and traveling seals may use various features of their environment to reach their destination including geomagnetic fields, water and wind currents, the position of the sun and moon and the taste and temperature of the water. Baleen whales famously migrate very long distances into tropical waters to give birth and raise young, possibly to prevent predation by killer whales. The gray whale has

1924-415: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Los_Angeles_Museum&oldid=1140872325 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Natural History Museum of Los Angeles County The museum

1976-576: The longest recorded migration of any mammal, with one traveling 14,000 miles (23,000 km) from the Sea of Okhotsk to the Baja Peninsula . During the winter, manatees living at the northern end of their range migrate to warmer waters. Marine mammals have a number of physiological and anatomical features to overcome the unique challenges associated with aquatic living. Some of these features are very species-specific. Marine mammals have developed

2028-401: The lower stems of kelp , causing the kelp to drift away and die. Loss of the habitat and nutrients provided by kelp forests leads to profound cascade effects on the marine ecosystem. North Pacific areas that do not have sea otters often turn into urchin barrens , with abundant sea urchins and no kelp forest. Reintroduction of sea otters to British Columbia has led to a dramatic improvement in

2080-476: The majority of their time in the water but need to return to land for important activities such as mating , breeding and molting . Sea otters tend to live in kelp forests and estuaries. In contrast, the polar bear is mostly terrestrial and only go into the water on occasions of necessity, and are thus much less adapted to aquatic living. The diets of marine mammals vary considerably as well; some eat zooplankton , others eat fish, squid, shellfish, or seagrass, and

2132-475: The mineralogy and Pleistocene paleontology are the most esteemed, the latter thanks to the wealth of specimens collected from The La Brea Tar Pits. The museum has almost 30 million specimens representing marine zoology. These include one of the largest collections of marine mammal remains in the world, housed in a warehouse off site, which at over 5,000 specimens is second in size only to that of The Smithsonian . The museum's collection of historical documents

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2184-459: The museum plans to open a new wing of the museum called the NHM Commons. The commons will be approximately 60,000 square feet consisting of renovations, new constructions, and landscaping; it will be located on the southwest side of the museum. The commons aims to be a community space with a combination of indoor and outdoor experiences including a welcome area, a lobby with a shop, a theater,

2236-541: The oceans, which have also evolved several specialized aquatic traits. In addition to the above, several other mammals have a great dependency on the sea without having become so anatomically specialized, otherwise known as "quasi-marine mammals". This term can include: the greater bulldog bat ( Noctilio leporinus ), the fish-eating bat ( Myotis vivesi ), the arctic fox ( Vulpes lagopus ) which often scavenges polar bear kills, coastal gray wolf ( Canis lupus ) populations which predominantly eat salmon and marine carcasses,

2288-858: The ongoing effects of global warming degrade Arctic environments. Procaviidae Elephantidae Dugongidae (dugongs) Trichechus manatus (West Indian manatee) Trichechus senegalensis (African manatee) Trichechus inunguis (Amazonian manatee; freshwater species) Hippopotamidae Mysticeti (baleen whales) Odontoceti (toothed whales, except river dolphins ) Ruminantia Perissodactyla Pholidota Feliformia Canidae Ursus maritimus (polar bear) all other ursids Enhydra lutris (sea otter) Lontra felina (marine otter) † Neogale macrodon (sea mink) all other mustelids Otariidae (eared seals) Odobenidae (walruses) Phocidae (earless seals) The term "marine mammal" encompasses all mammals whose survival depends entirely or almost entirely on

2340-621: The open ocean, and species like the sperm whale may dive to depths of −1,000 to −2,500 feet (−300 to −760 m) in search of food. Sirenians live in shallow coastal waters, usually living 30 feet (9.1 m) below sea level. However, they have been known to dive to −120 feet (−37 m) to forage deep-water seagrasses . Sea otters live in protected areas, such as rocky shores, kelp forests , and barrier reefs , although they may reside among drift ice or in sandy, muddy, or silty areas. Many marine mammals seasonally migrate. Annual ice contains areas of water that appear and disappear throughout

2392-541: The polar bear might not be considered a species under some species concepts . In general, terrestrial amniote invasions of the sea have become more frequent in the Cenozoic than they were in the Mesozoic. Factors contributing to this trend include the increasing productivity of near-shore marine environments, and the role of endothermy in facilitating this transition. Marine mammals are widely distributed throughout

2444-412: The same site in the fall. Since 2017, the museum has hosted a special exhibit about P-22 , the mountain lion that lived in nearby Griffith Park . Over the years, the museum has built additions onto its original building. Originally dedicated when The Natural History Museum opened in 1913, the rotunda is one of the museum's most elegant and popular spaces. Lined with marble columns and crowned by

2496-474: The target for commercial industry, leading to a sharp decline in all populations of exploited species, such as whales and seals. Commercial hunting led to the extinction of the Steller's sea cow , sea mink , Japanese sea lion and Caribbean monk seal . After commercial hunting ended, some species, such as the gray whale and northern elephant seal , have rebounded in numbers; conversely, other species, such as

2548-459: The water. Polar bears, otters, and fur seals have long, oily, and waterproof fur in order to trap air to provide insulation. In contrast, other marine mammals—such as whales, dolphins, porpoises, manatees, dugongs, and walruses—have lost long fur in favor of a thick, dense epidermis and a thickened fat layer (blubber) to prevent drag . Wading and bottom-feeding animals (such as manatees) need to be heavier than water in order to keep contact with

2600-409: The whale's interest, be within a certain size range so that the baleen plates can filter it, and be slow enough so that it cannot escape. Otters are the only marine animals that are capable of lifting and turning over rocks, which they often do with their front paws when searching for prey. The sea otter may pluck snails and other organisms from kelp and dig deep into underwater mud for clams . It

2652-483: The year as the weather changes, and seals migrate in response to these changes. In turn, polar bears must follow their prey. In Hudson Bay , James Bay , and some other areas, the ice melts completely each summer (an event often referred to as "ice-floe breakup"), forcing polar bears to go onto land and wait through the months until the next freeze-up. In the Chukchi and Beaufort seas, polar bears retreat each summer to

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2704-515: Was a museum association founded in 1910. Its distinctive main building with fitted marble walls and domed and colonnaded rotunda, is on The National Register of Historic Places . Additional wings opened in 1925, 1930, 1960, and 1976. The museum split in 1961 into The Los Angeles County Museum of History and Science and the Los Angeles County Museum of Art (LACMA). LACMA moved to new quarters on Wilshire Boulevard in 1965, and

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