A
bone bed is any
geologicalGeology is the science and study of the solid and liquid matter that constitutes the Earth. The field of geology encompasses the study of the composition, structure, physical properties, dynamics, and history of Earth materials, and the processes by which they are formed, moved, and changed...
stratumIn geology and related fields, a stratum is a layer of rock or soil with internally consistent characteristics that distinguishes it from contiguous layers. Each layer is generally one of a number of parallel layers that lie one upon another, laid down by natural forces. They may extend over...
or
depositDeposition is the geological process by which material is added to a landform or land mass. Fluids such as wind and water, as well as sediment gravity flows, transport previously eroded sediment, which, at the loss of enough kinetic energy in the fluid, is deposited, building up layers of...
that contains
boneBones are rigid organs that form part of the endoskeleton of vertebrates. They function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
s of whatever kind. Inevitably, such deposits are
sedimentarySedimentary rock is the type of rock that is formed by sedimentation of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....
in nature. Not a formal term, it tends to be used more to describe especially dense collections. It is also applied to
brecciaBreccia is a rock composed of angular fragments of minerals or rocks in a matrix , that may be similar or different in composition to the fragments. The word is a loan from italian, and in that language indicates both loose gravel and stone made by cemented gravel...
ted and
stalagmiticA stalagmite is a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate. The corresponding formation on the ceiling of a cave is known as a stalactite...
deposits on the floor of caves, which frequently contain osseous remains.
In a more restricted sense, the term is used to connote certain thin layers of bony fragments, which occur in well-defined geological strata. One of the best-known of these is the Ludlow Bone Bed, which is found at the base of the Downton Sandstone in the
Upper Ludlow seriesThe Ludlow Group are rocks deposited during the Ludlow period of the Silurian in Great Britain. This group contains the following formations in descending order:#Cilestones, Downton Castle sandstones ,#Ledbury shales 270 ft./83 m),...
. At
LudlowLudlow is a market town in Shropshire, England close to the Wales-England border and in the Welsh Marches. It lies within a bend of the River Teme, on its eastern bank, forming an area of 350 acres and centred on a small hill. Atop this hill is the site of Ludlow Castle and the market place...
(
EnglandEngland is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west and the North Sea to the east, with the English Channel to the south separating it from continental...
) itself, two such beds are actually known, separated by about . of strata. Although quite thin, the Ludlow Bone Bed can be followed from that town into
GloucestershireGloucestershire is a county in South West England. The county comprises part of the Cotswold Hills, part of the flat fertile valley of the River Severn, and the entire Forest of Dean....
, for a distance of . It is almost completely made up of fragments of
spinesIn biology, spine or spiny may refer to:*Spine , needle-like structures in plants*Spine , needle-like structures in animalsSpine may also refer to:*Vertebral column, spine in anatomy, the backbone...
,
teethTeeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to tear, scrape, and chew food. Some animals, particularly carnivores, also use teeth for hunting or defense. The roots of teeth are covered by gums...
and
scalesIn most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
of ganoid fish. Another well-known bed, formerly known as the Bristol or Lias Bone Bed, exists in the form of several thin layers of
micaThe mica group of sheet silicate minerals includes several closely related materials having highly perfect basal cleavage. All are monoclinic with a tendency towards pseudo-hexagonal crystals and are similar in chemical composition...
ceous
sandstoneSandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains. Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any color, but the most common colors are tan, brown, yellow,...
, with the remains of fish and saurians, which occur in the Rhaetic Black Paper Shales that lie above the
KeuperThe Keuper is a lithostratigraphic unit in the subsurface of large parts of west and central Europe. The Keuper consists of dolostone, shales or claystones and evaporites that were deposited during the Middle and Late Triassic epochs...
marlMarl or marlstone is a calcium carbonate or lime-rich mud or mudstone which contains variable amounts of clays and aragonite. Marl was originally an old term loosely applied to a variety of materials, most of which occur as loose, earthy deposits consisting chiefly of an intimate mixture of clay...
s, in the south-west of England. It is noteworthy that a similar bone bed has been traced on the same geological horizon in Brunswick,
HanoverHanover or Hannover , on the river Leine, is the capital of the federal state of Lower Saxony , Germany and was once by personal union the family seat of the Hanoverian Kings of Great Britain, in their dignities as the dukes of Brunswick-Lüneburg Hanover or Hannover , on the river Leine, is...
(
GermanyGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
) and in
FranconiaFranconia is a region of Germany comprising the northern parts of the modern state of Bavaria, a part of southern Thuringia, and a much smaller region in northeastern Baden-Württemberg called Heilbronn-Franken...
. A bone bed has also been observed at the base of the
CarboniferousThe Carboniferous is a geologic period and system that extends from the end of the Devonian period, about 359.2 ± 2.5 Ma , to the beginning of the Permian period, about 299.0 ± 0.8 Ma ....
limestoneLimestone is a sedimentary rock composed largely of the mineral calcite . The deposition of limestone strata is often a by-product and indicator of biological activity in the geologic record...
series, in certain parts of the south-west of England.
Bone beds are also recorded in
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
,
South AmericaSouth America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere...
,
MongoliaMongolia is a landlocked country in East and Central Asia. It borders Russia to the north and the People's Republic of China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only 24 miles from Kazakhstan's eastern tip. Ulan Bator,...
and
ChinaChina is a cultural region, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....
. Examples are: the
MapusaurusMapusaurus was a giant carnosaurian dinosaur from the early Late Cretaceous of what is now Argentina. It was similar in size to its close relative Giganotosaurus, with the largest known specimens measuring over 12.2 meters in length and weighing over 3 tons...
bone bed at Canadon de Gato, in
ArgentinaArgentina, officially the Argentine Republic , is the second largest country in South America, constituted as a federation of 23 provinces and an autonomous city, Buenos Aires. It is the eighth largest country in the world by land area and the largest among Spanish-speaking nations, though Mexico,...
, the
AllosaurusAllosaurus is a genus of large theropod dinosaur that lived 155 to 145 million years ago, in the late Jurassic period . The name Allosaurus means "different lizard" and is derived from the Greek αλλος/allos and σαυρος/sauros...
-dominated
Cleveland Lloyd Dinosaur QuarryThe Cleveland Lloyd Dinosaur Quarry National Natural Landmark, located in The San Rafael Swell, near Cleveland, Utah contains the densest concentration of Jurassic dinosaur fossils ever found, Well over 15,000 bones have been excavated from this Jurassic 'predator trap' and there are many...
of
UtahUtah is a western state of the United States. It was the 45th state admitted to the Union, on January 4, 1896. Approximately 80 percent of Utah's 2,736,424 people live along the Wasatch Front, centering around Salt Lake City. In contrast, vast expanses of the state are nearly uninhabited, making...
, the
Dinosaur National MonumentDinosaur National Monument is a National Monument located on the southeast flank of the Uinta Mountains on the border between Colorado and Utah at the confluence of the Green and Yampa Rivers. Although most of the monument area is in Moffat County, Colorado, the Dinosaur Quarry is located in Utah...
on the boundary of Utah and
ColoradoColorado is a U.S. state located in the Rocky Mountain region of the United States of America. It may also be considered to be part of the Western and Southwestern regions of the United States. Colorado entered statehood in 1876 and was nicknamed the “Centennial State”...
, an
AlbertosaurusAlbertosaurus is a genus of tyrannosaurid theropod dinosaur that lived in western North America during the Late Cretaceous Period, more than 70 million years ago. The type species, A. sarcophagus, was restricted in range to the modern-day Canadian province of Alberta, after which the genus is...
bone bed from
AlbertaAlberta is one of Canada's prairie provinces. It became a province on September 1, 1905.Alberta is located in western Canada, bounded by the provinces of British Columbia to the west and Saskatchewan to the east, the Northwest Territories to the north, and the U.S. state of Montana to the south....
, a
DaspletosaurusDaspletosaurus is a genus of tyrannosaurid theropod dinosaur that lived in western North America between 77 and 73 million years ago, during the Late Cretaceous Period. Fossils of the only named species were found in Alberta, although other possible species from Alberta, Montana and New Mexico...
bone bed from
MontanaMontana is a state in the Western United States. The western third of the state contains numerous mountain ranges; other 'island' ranges are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
, the
CenozoicThe Cenozoic Era The Cenozoic (also Cænozoic or Cainozoic) Era The Cenozoic (also Cænozoic or Cainozoic) Era (meaning "new life" (Greek (kainos), "new", and (zoe), "life"), is the most recent of the three classic geological eras and covers the period from 65.5 million years ago to the...
John Day Fossil BedsJohn Day Fossil Beds National Monument is a park in eastern Oregon. Located within the John Day River Basin, this U.S. National Monument is world renowned for its well preserved, remarkably complete record of fossil plants and animals, a record that spans more than 40 of the 65 million years of...
of
OregonOregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
and the
Nemegt BasinThe Nemegt Basin is situated in the northwestern part of the Gobi Desert, in the Ömnögovi Province in the southern part of Mongolia. It is known locally as the valley of the dragons, since it is a source of many fossil finds, including dinosaurs, dinosaur eggs and trace fossils.The main geological...
in the
Gobi DesertThe Gobi is the largest desert region in Asia. It covers parts of northern and northwestern China, and of southern Mongolia...
region of
MongoliaMongolia is a landlocked country in East and Central Asia. It borders Russia to the north and the People's Republic of China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only 24 miles from Kazakhstan's eastern tip. Ulan Bator,...
.