''Edaphosaurus'' (, meaning "pavement lizard" for dense clusters of teeth) is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
edaphosaurid synapsid
Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes reptil ...
s that lived in what is now
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
and
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
around 303.4 to 272.5
million years ago
The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds.
Usage
Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...
,
during the
Late Carboniferous
Late may refer to:
* LATE, an acronym which could stand for:
** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia
** Local-authority trading enterprise, a New Zealand business law
** Local average treatment effect, ...
to
Early Permian 01 or '01 may refer to:
* The year 2001, or any year ending with 01
* The month of January
* 1 (number)
Music
* '01 (Richard Müller album), 01'' (Richard Müller album), 2001
* 01 (Son of Dave album), ''01'' (Son of Dave album), 2000
* 01 (Urban ...
.
American
American(s) may refer to:
* American, something of, from, or related to the United States of America, commonly known as the "United States" or "America"
** Americans, citizens and nationals of the United States of America
** American ancestry, pe ...
paleontologist
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...
Edward Drinker Cope
Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontologist, comparative anatomist, herpetologist, and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested ...
first described ''Edaphosaurus'' in 1882,
naming it for the "dental pavement" on both the upper and lower jaws, from the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
' ("ground"; also "pavement") and (') ("lizard").
''Edaphosaurus'' is important as one of the earliest-known, large, plant-eating (
herbivorous
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...
),
amniote
Amniotes are a clade of tetrapod vertebrates that comprises sauropsids (including all reptiles and birds, and extinct parareptiles and non-avian dinosaurs) and synapsids (including pelycosaurs and therapsids such as mammals). They are disti ...
tetrapods
Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (pelycosaurs, extinct therapsids ...
(four-legged land-living
vertebrates
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...
). In addition to the large tooth plates in its jaws, the most characteristic feature of ''Edaphosaurus'' is a sail on its back. A number of other synapsids from the same time period also have tall dorsal sails, most famously the large
apex predator
An apex predator, also known as a top predator, is a predator at the top of a food chain, without natural predators of its own.
Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the highest trophic lev ...
''
Dimetrodon
''Dimetrodon'' ( or ,) meaning "two measures of teeth,” is an extinct genus of non-mammalian synapsid that lived during the Cisuralian (Early Permian), around 295–272 million years ago (Mya). It is a member of the family Sphenacodontid ...
''. However, the sail on ''Edaphosaurus'' is different in shape and morphology. The first fossils of ''Edaphosaurus'' came from the
Texas Red Beds in
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, with later finds in
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ker ...
,
Oklahoma
Oklahoma (; Choctaw language, Choctaw: ; chr, ᎣᎧᎳᎰᎹ, ''Okalahoma'' ) is a U.S. state, state in the South Central United States, South Central region of the United States, bordered by Texas on the south and west, Kansas on the nor ...
,
West Virginia
West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the Bur ...
, and
Ohio
Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...
. Fragmentary fossils attributed to ''Edaphosaurus'' have also been found in eastern
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
in
Central Europe
Central Europe is an area of Europe between Western Europe and Eastern Europe, based on a common historical, social and cultural identity. The Thirty Years' War (1618–1648) between Catholicism and Protestantism significantly shaped the area' ...
.
Etymology
![Edaphosaurus NT small](https://upload.wikimedia.org/wikipedia/commons/5/50/Edaphosaurus_NT_small.jpg)
The name ''Edaphosaurus'', meant as "pavement lizard",
[Miller, S. A. (1889). ''North American Geology and Palaeontology for the Use of Amateurs, Students, and Scientists.'' Western Methodist Book Concern, Cincinnati. 718 pp.] is often translated inaccurately as "earth lizard", "ground lizard", or "foundation lizard" based on other meanings for the Greek ', such as "soil, earth, ground, land, base" used in
neo-Latin
New Latin (also called Neo-Latin or Modern Latin) is the revival of Literary Latin used in original, scholarly, and scientific works since about 1500. Modern scholarly and technical nomenclature, such as in zoological and botanical taxonomy ...
scientific nomenclature (
edaphology
Edaphology (from Greek , ''edaphos'', "ground",, ''-logia'') is concerned with the influence of soils on living beings, particularly plants.
It is one of two main divisions of soil science, the other being pedology. Edaphology includes the study ...
). However, older names in paleontology, such as ''
Edaphodon'' Buckland, 1838 "pavement tooth" (a fossil fish), match Cope's clearly intended meaning "pavement" for Greek ''edaphos'' in reference to the animal's teeth.
Description and paleobiology
![Edaphosaurus Scale](https://upload.wikimedia.org/wikipedia/commons/4/4e/Edaphosaurus_Scale.svg)
''Edaphosaurus'' species measured from in length and weighed over 300 kg (660
lb).
In keeping with its tiny head, the
cervical vertebrae
In tetrapods, cervical vertebrae (singular: vertebra) are the vertebrae of the neck, immediately below the skull. Truncal vertebrae (divided into thoracic and lumbar vertebrae in mammals) lie caudal (toward the tail) of cervical vertebrae. In ...
are reduced in length, while the
dorsal vertebrae
In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervical ...
are massive, the tail is deep, the limbs are short and robust, and the ribs form a wide ribcage. Like most herbivores, ''Edaphosaurus'' would have had a capacious gut and symbiotic bacteria to aid in the breakdown of cellulose and other indigestible plant material.
[ Like its more famous relative '']Dimetrodon
''Dimetrodon'' ( or ,) meaning "two measures of teeth,” is an extinct genus of non-mammalian synapsid that lived during the Cisuralian (Early Permian), around 295–272 million years ago (Mya). It is a member of the family Sphenacodontid ...
'', ''Edaphosaurus'' had a sail-like fin that was supported by bones of the 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, ...
. ''Edaphosaurus'' differs from ''Dimetrodon'' in having cross-bars on the spines that supported its fin.
Skull
The head of ''Edaphosaurus'' was short, relatively broad, triangular in outline, and remarkably small compared to its body size. The deep lower jaw likely had powerful muscles and the marginal teeth along the front and sides of its jaws had serrated tips, helping ''Edaphosaurus'' to crop bite-sized pieces from tough terrestrial plants. Back parts of the roof of the mouth and the inside of the lower jaw held dense batteries of peglike teeth, forming a broad crushing and grinding surface on each side above and below. Its jaw movements were propalinal (front to back). Early descriptions suggested that ''Edaphosaurus'' fed on invertebrates such as mollusks, which it would have crushed with its tooth plates. However, paleontologists now think that ''Edaphosaurus'' ate plants, although tooth-on-tooth wear between its upper and lower tooth plates indicates only "limited processing of food" compared to other early plant-eaters such as ''Diadectes
''Diadectes'' (meaning ''crosswise-biter'') is an extinct genus of large reptiliomorphs or synapsids that lived during the early Permian period (Artinskian-Kungurian stages of the Cisuralian epoch, between 290 and 272 million years ago). ''Diade ...
'', a large nonamniote reptiliomorph
Reptiliomorpha (meaning reptile-shaped; in PhyloCode known as ''Pan-Amniota'') is a clade containing the amniotes and those tetrapods that share a more recent common ancestor with amniotes than with living amphibians ( lissamphibians). It was de ...
(Diadectidae
Diadectidae is an extinct family of early tetrapods that lived in what is now North America and Europe during the Late Carboniferous and Early Permian in Asia during the Late Permian. They were the first herbivorous tetrapods, and also the first ...
) that lived at the same time. Early members of the Edaphosauridae
Edaphosauridae is a family of mostly large (up to 3 meters or more) Late Carboniferous to Early Permian synapsids. Edaphosaur fossils are so far known only from North America and Europe.
Characteristics
They were the earliest known herbivorous a ...
such as '' Ianthasaurus'' lacked tooth plates and ate insects.
Sail
The sail along the back of ''Edaphosaurus'' was supported by hugely elongated neural spines from neck to lumbar region, connected by tissue in life. When compared with the sail of ''Dimetrodon'', the vertebral spines are shorter and heavier, and bear numerous small crossbars. ''Edaphosaurus'' and other members of the Edaphosauridae evolved tall dorsal sails independently of sail-back members of the Sphenacodontidae
Sphenacodontidae (Greek: "wedge point tooth family") is an extinct family of small to large, advanced, carnivorous, Late Pennsylvanian to middle Permian pelycosaurs. The most recent one, ''Dimetrodon angelensis'', is from the late Kungurian or ...
such as ''Dimetrodon'' and ''Secodontosaurus
''Secodontosaurus'' (meaning "cutting-tooth lizard") is an extinct genus of "pelycosaur" synapsids that lived from between about 285 to 272 million years ago during the Early Permian. Like the well known ''Dimetrodon'', ''Secodontosaurus'' is a c ...
'' that lived at the same time, an unusual example of parallel evolution
Parallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure.Zhang, J. and Kumar, S. 1997Detection of convergent and paral ...
. The of the sail in both groups is still debated. Researchers have suggested that such sails could have provided camouflage, wind-powered sailing over water, anchoring for extra muscle support and rigidity for the backbone, protection against predator attacks, fat-storage areas, body-temperature control surfaces, or sexual display and species recognition. The height of the sail, curvature of the spines, and shape of the crossbars are distinct in each of the described species of ''Edaphosaurus'' and show a trend for larger and more elaborate (but fewer) projecting processes over time. The possible function (or functions) of the bony tubercles on the spines remains uncertain. Romer and Price suggested that the projections on the spines of ''Edaphosaurus'' might have been embedded in tissue under the skin and might have supported food-storage or fat similar to the hump of a camel. Bennett argued that the bony projections on ''Edaphosaurus'' spines were exposed and could create air turbulence for more efficient cooling over the surface of the sail to regulate body temperature. Recent research that examined the microscopic bone structure of the tall neural spines in edaphosaurids has raised doubts about a thermoregulatory role for the sail and suggests that a display function is more plausible.
Growth and Metabolism
A study comparing the microscopic bone histology of the vertebral centra of ''Edaphosaurus'' and ''Dimetrodon'' found that the plant-eating ''Edaphosaurus'' "grew distinctly more slowly" than the predator ''Dimetrodon'', which had a higher growth rate, reflecting an "elevated metabolism". Earlier studies of ''Edaphosaurus'' limb bones had also indicated slower growth and a lower metabolism, reflecting an ectotherm
An ectotherm (from the Greek () "outside" and () "heat") is an organism in which internal physiological sources of heat are of relatively small or of quite negligible importance in controlling body temperature.Davenport, John. Animal Life a ...
ic (cold-blooded) animal, although the plant-eating early synapsid caseids
Caseidae are an extinct family of basal synapsids that lived from the Late Carboniferous to Middle Permian between about 300 and 265 million years ago. Fossils of these animals come from the south-central part of the United States ( Texas, ...
had a lower growth rate than ''Edaphosaurus''. Evidence of growth rates include the number of blood vessels in the bones (with more vascularization in the rapidly growing ''Dimetrodon'') and the presence of lamellar bone in the cancellous part. In contrast to slow growth in overall body size and in most bones, the histology of the tall dorsal spines on ''Edaphosaurus'' suggests that the projecting bony tubercles developed "by sudden, rapid growth over a few seasons", unlike the incremental growth of the tubercles in the earlier edaphosaurid ''Ianthasaurus''.
Species
Discovery and classification
Edward Drinker Cope named and described ''Edaphosaurus'' ("pavement lizard") in 1882, based on a crushed skull and a left lower jaw from the Texas Red Beds. He noted in particular the "dense body of teeth" on both the upper and lower jaws, and used the term "dental pavement" in a table in his description. The type species name ''pogonias'' means "bearded" in Greek, referring to the enlarged inward sloping chin on the lower jaw. Cope classified ''Edaphosaurus'' as a member of his Pelycosauria
Pelycosaur ( ) is an older term for Basal (phylogenetics), basal or primitive Late Paleozoic synapsids, excluding the therapsids and their descendants. Previously, the term ''mammal-like reptile'' had been used, and pelycosaur was considered an ...
and created the new family Edaphosauridae. The type material did not include any of the post-cranial skeleton apart from an axis vertebra and Cope was unaware of the animal's large sail, a feature then known only for ''Dimetrodon''.
In 1886, Cope erected the new genus ''Naosaurus'' "ship lizard" (from Greek ''naos'' "ship") for skeletal remains similar to those of the long-spined ''Dimetrodon'', but with distinctive "transverse processes or branches, which resemble the yardarms of a ship's mast". He speculated that "the yardarms were connected by membranes with the neural spine or mast, thus serving the animal as a sail with which he navigated the waters of the Permian lakes". He recognized three species: ''Naosaurus claviger'' "club-bearer" (for the projections on its spines; now considered a synonym of ''Edaphosaurus pogonias''); ''Naosaurus cruciger'' "cross-bearer" (for the projections on its spines; first described by Cope as ''Dimetrodon cruciger'' in 1878; now ''Edaphosaurus cruciger'', the largest species in size); and ''Naosaurus microdus'' "small tooth" (first described as ''Edaphosaurus microdus'' in 1884). Cope noted some incomplete skull material found associated with the specimens of ''N. claviger'' and ''N. microdus'', but thought ''Naosaurus'' was distinct from ''Edaphosaurus''. He later decided that ''Naosaurus'' must have had a large carnivorous skull similar to ''Dimetrodon'', although he had no direct fossil proof. In 1910, German paleontologist Otto Jaekel
Otto Max Johannes Jaekel (21 February 1863 – 6 March 1929) was a German paleontologist and geologist.
Biography
Jaekel was born in Neusalz (Nowa Sól), Prussian Silesia, the son of a builder and the youngest of seven children. He studied at ...
reported remains near Dresden
Dresden (, ; Upper Saxon: ''Dräsdn''; wen, label=Upper Sorbian, Drježdźany) is the capital city of the German state of Saxony and its second most populous city, after Leipzig. It is the 12th most populous city of Germany, the fourth larg ...
in Saxony
Saxony (german: Sachsen ; Upper Saxon: ''Saggsn''; hsb, Sakska), officially the Free State of Saxony (german: Freistaat Sachsen, links=no ; Upper Saxon: ''Freischdaad Saggsn''; hsb, Swobodny stat Sakska, links=no), is a landlocked state of ...
, which he called ''Naosaurus credneri''.
In 1907, American paleontologist Ermine Cowles Case
Ermine Cowles Case (1871–1953), invariably known as E.C. Case, was a prominent American paleontologist in the second generation that succeeded Othniel Charles Marsh and Edward Drinker Cope. A graduate of the University of Kansas, with a PhD ...
suggested that the skull of ''Edaphosaurus'' might belong with skeletons called ''Naosaurus'', based on a specimen found in 1906 that appeared to associate elements of both. In 1913, Samuel Wendell Williston
Samuel Wendell Williston (July 10, 1852 – August 30, 1918) was an American educator, entomologist, and paleontologist who was the first to propose that birds developed flight cursorially (by running), rather than arboreally (by leaping from tr ...
and Case described the new species ''Edaphosaurus novomexicanus'' from a fairly complete specimen unearthed in New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ker ...
in 1910, in which a sailbacked ''Naosaurus''-type skeleton was found with a small ''Edaphosaurus''-type skull. The older generic name ''Edaphosaurus'' Cope, 1882 became the valid one.
In 1940, paleontologists Alfred Sherwood Romer
Alfred Sherwood Romer (December 28, 1894 – November 5, 1973) was an American paleontologist and biologist and a specialist in vertebrate evolution.
Biography
Alfred Romer was born in White Plains, New York, the son of Harry Houston Romer an ...
and Llewellyn Ivor Price
Llewellyn Ivor Price (October 9, 1905 – June 9, 1980) was one of the first Brazilian paleontologists. His work contributed not only to the development of Brazilian but also to global paleontology. He collected '' Staurikosaurus'', the first ...
named the new species ''Edaphosaurus boanerges'' ("thunderous orator") – an ironic reference to the remarkably small size of the holotype lower jaw on a composite skeleton originally mounted in the Museum of Comparative Zoology
A museum ( ; plural museums or, rarely, musea) is a building or institution that cares for and displays a collection of artifacts and other objects of artistic, cultural, historical, or scientific importance. Many public museums make these ...
(Harvard University
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...
) with the head restored based on the larger species ''Edaphosaurus cruciger''.
In 1979, paleontologist David Berman erected ''Edaphosaurus colohistion'' ("stunted sail") for an early species with a relatively small sail, based on fossils from West Virginia
West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the Bur ...
.
Reassigned species
Other proposed species of ''Edaphosaurus'' have been based on more fragmentary material that cannot be rigorously diagnosed to a genus/species level, but which may nonetheless represent edaphosaurids. The nominal species ''Naosaurus raymondi'' was assigned to ''Edaphosaurus'' by Romer and Price (1940), but Modesto and Reisz (1990) designated it a ''nomen vanum'', and Spindler (2015) considered it probably referable to '' Ianthasaurus'' due to its age and stratigraphy. The taxon ''Naosaurus mirabilis'' Fritsch, 1895 from the Czech Republic was given its own genus '' Bohemiclavulus'' by Spindler ''et al.'' (2019).
In popular culture
The strange appearance of ''Edaphosaurus'' with its distinctive dorsal sail composed of tall spines studded with bony knobs has made it a popular subject for scientific reconstructions and paleoart in museums and in books. However, confusion over the animal's skull dating back to Cope's ideas about "''Naosaurus''" and over other details led to a long history of scientific and artistic errors that lasted in some cases into the 1940s. The correct scientific name ''Edaphosaurus'' (rather than "''Naosaurus''") also was not used consistently until the 1940s.
At the urging of paleontologist Henry Fairfield Osborn
Henry Fairfield Osborn, Sr. (August 8, 1857 – November 6, 1935) was an American paleontologist, geologist and eugenics advocate. He was the president of the American Museum of Natural History for 25 years and a cofounder of the American Euge ...
, American paleoartist Charles R. Knight
Charles Robert Knight (October 21, 1874 – April 15, 1953) was an American wildlife and paleoartist best known for his detailed paintings of dinosaurs and other prehistoric animals. His works have been reproduced in many books and are currently ...
consulted with Edward Drinker Cope in person in early 1897 about a set of illustrations of prehistoric reptiles, one of Cope's specialties. Shortly after, Knight reconstructed ''Edaphosaurus'' (as "''Naosaurus''") with a ''Dimetrodon'' skull that Cope had previously referred to that genus in error. This painting was commissioned for the American Museum of Natural History in 1897 and was reprinted for Cope's obituary in the November 1898 issue of ''The Century Magazine''. Knight later created a more accurate revised version of the painting that turned "''Naosaurus''" into ''Dimetrodon'', with a corrected head and teeth, and a sail with smooth, unbarred spines. He also turned the ''Dimetrodon'' in the original background into ''Edaphosaurus'' (still called "''Naosaurus''" at the time) with a different head and a sail with crossbars.
German paleontologist Otto Jaekel argued in 1905 that there was no direct scientific evidence that the tall dorsal spines on ''Dimetrodon'' and "''Naosaurus''" were bound in a web of skin like a sail or fin (as portrayed by Cope, Knight, and others) and proposed instead that the long bony projections served as an array of separated spines to protect the animals, which allegedly could roll up like hedgehogs. Spiny-backed reconstructions of "''Naosaurus''" (with a large carnivore's head) appeared in different German sources, including as a tile mosaic on the façade of the Aquarium Berlin
The Aquarium Berlin in Berlin is one of Germany's largest aquariums. The aquarium was built in 1913 as part of the Berlin Zoological Garden complex. Since its opening the Zoo-Aquarium has been ranked among the public aquariums with the world’s ...
in 1913 (destroyed in World War II and later recreated).
Nearly complete specimens of ''Dimetrodon'' and ''Edaphosaurus'' (as "''Naosaurus''") had not been found yet by the first decade of the 20th century when American paleontologist E.C. Case produced his major monograph on the Pelycosauria in 1907.[ Case argued that the apparent lack of any associated elongate and cylindrical tail bones with the known fossils meant that ''Dimetrodon'' and "''Naosaurus''" must have had short tails in life. (Earlier, Cope had assumed that the animals had long tails as in most reptiles, an idea seen from his sketches and his advice to Charles R. Knight in 1897.) Based on the authority of Case, museums and artists at the time restored "''Naosaurus''" with a short tail. New fossil finds and research by A.S. Romer in the 1930s and 1940s showed that both ''Dimetrodon'' and ''Edaphosaurus'' had long tails, a feature similar to other "pelycosaurs" and seen as primitive.]
The American Museum of Natural History
The American Museum of Natural History (abbreviated as AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. In Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 26 inter ...
mounted the first full skeletal reconstruction of ''Edaphosaurus'' as "''Naosaurus claviger''" (a synonym of ''Edaphosaurus pogonias'') for public display in 1907 under the scientific direction of H.F. Osborn, along with W.D. Matthew. The main part of the "''Naosaurus''" skeleton was a set of dorsal vertebrae with high spines (AMNH 4015) from a partial ''Edaphosaurus pogonias'' specimen found by the fossil collector Charles H. Sternberg in Hog Creek, Texas in 1896. Because of the still incomplete knowledge of ''Edaphosaurus'' at the time, the rest of the mount was a "conjectural" composite of various real fossil bones collected in different places with other parts recreated in plaster, including a skull (AMNH 4081) based on ''Dimetrodon'' (per E.D. Cope, and despite Case's already expressed doubts about such a skull for "''Naosaurus''") and a hypothetical short tail (per Case). As "''Naosaurus''" was thought to be a close relative of ''Dimetrodon'' rather than ''Edaphosaurus'', slender limbs (AMNH 4057) probably belonging to ''Dimetrodon dollovianus'' were also mounted with this composite specimen, rather than the correct, stockier limbs now known for ''Edaphosaurus''. The big ''Dimetrodon''-derived skull on the museum skeleton was later replaced with one modeled on ''Edaphosaurus cruciger'', based on more updated research. The museum eventually dismantled the entire composite restoration and by the 1950s only displayed the original set of ''Edaphosaurus pogonias'' sail vertebrae alone on the wall in Brontosaur Hall next to an accurate, fully mounted fossil skeleton of the smaller species ''Edaphosaurus boanerges'' (a nearly complete specimen (AMNH 7003) collected from Archer County, Texas, by A.S. Romer in 1939). The fossil ''Edaphosaurus pogonias'' sail spines (AMNH 4015) were remounted in the 1990s with a recreated skull (but without other skeletal parts) in a metal armature shaped in the outline of the entire animal as part of the new Hall of Primitive Mammals, which opened at the American Museum of Natural History in 1996 after major renovations.
Charles R. Knight had produced a small sculpture of a living "''Naosaurus''" in 1907 based on the speculative American Museum of Natural History mount. The model retained a ''Dimetrodon''-like flesh-eater's head but differed from his earlier 1897 painted reconstruction in having a curved shape to the sail and a short tail.
The May 4, 1907 issue of ''Scientific American''
featured a cover painting by Knight depicting a revised version of "''Naosaurus''" and an article (pages 368 and 370) entitled "''Naosaurus: a Fossil Wonder''", which described the restoration of the composite skeleton at the American Museum of Natural History and the creation of Knight's model, both under Osborn's direction.
The inaccuracy of much of Osborn's composite reconstruction of "''Naosaurus''" was detailed by E.C. Case in 1914 with a revised description of ''Edaphosaurus'' based on additional fossil material, including large parts of a skeleton with limb bones and a crushed skull, which Case had discovered in Archer County, Texas, in 1912 and brought to the University of Michigan
, mottoeng = "Arts, Knowledge, Truth"
, former_names = Catholepistemiad, or University of Michigania (1817–1821)
, budget = $10.3 billion (2021)
, endowment = $17 billion (2021)As o ...
. His reconstruction of ''Edaphosaurus cruciger'', as shown in a drawing, had a much smaller head (with teeth for crushing mollusks or plants), more robust limbs, and a somewhat longer tail than Osborn's carnivorous "''Naosaurus''" mount. Case also confirmed that ''Edaphosaurus'' was the valid name rather than "''Naosaurus''". Despite his corrections, the name "''Naosaurus''", and even the outdated and incorrect ''Dimetrodon''-like head, continued to appear in some popular sources.
In 1926, the Field Museum of Natural History
The Field Museum of Natural History (FMNH), also known as The Field Museum, is a natural history museum in Chicago, Illinois, and is one of the largest such museums in the world. The museum is popular for the size and quality of its educational ...
in Chicago hired Charles R. Knight to create a series of 28 murals
(worked on from 1926 through 1930) to depict life reconstructions of prehistoric animals in the different sections of the new fossil hall of the museum for ''Life Over Time''. One of the large murals depicted the Permian Period, with a group of five ''Dimetrodons'', and a single ''Edaphosaurus'', along with a group of ''Casea
''Casea'' is a genus of herbivorous caseid synapsids that lived during the late Lower Permian (Kungurian) in what is now Texas, United States. The genus is only represented by its type species, ''Casea broilii'', named by Samuel Wendell Willisto ...
'', basking in the sun surrounded by a large marsh. The Permian mural was finished in 1930. Paleontologist Elmer Riggs
Elmer Samuel Riggs (January 23, 1869 – March 25, 1963) was an American paleontologist known for his work with the Field Museum of Natural History in Chicago, Illinois.
Biography
He was born in Trafalgar, Indiana, and moved with his famil ...
described the new artistic addition in the March 1931 issue of the ''Field Museum News'' and used the name "''Naosaurus''" for ''Edaphosaurus'', described as "inoffensive, and given to feeding on plants". Knight's 1930 depiction of ''Edaphosaurus'', apart from its shortened tail, was much more accurate than his earlier images of "''Naosaurus''" for the American Museum of Natural History, incorporating a small head and a curved profile to the sail spines.
Artist Rudolph Zallinger depicted ''Edaphosaurus'' in a more scientifically updated form (with a long tail) alongside ''Dimetrodon'' and ''Sphenacodon
''Sphenacodon'' (meaning "wedge point tooth") is an extinct genus of synapsid that lived from about 300 to about 280 million years ago (Ma) during the Late Carboniferous and Early Permian periods. Like the closely related '' Dimetrodon'', ''Sphen ...
'' to represent the Permian period
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozo ...
in his famous '' The Age of Reptiles'' mural (1943-1947) at the Yale Peabody Museum
The Peabody Museum of Natural History at Yale University is among the oldest, largest, and most prolific university List of natural history museums, natural history museums in the world. It was founded by the philanthropist George Peabody in 1866 ...
. The mural was based on a smaller model version of the painting in egg tempera that later appeared in '' The World We Live In'' series published in ''Life
Life is a quality that distinguishes matter that has biological processes, such as signaling and self-sustaining processes, from that which does not, and is defined by the capacity for growth, reaction to stimuli, metabolism, energ ...
'' magazine in 1952 to 1954. The September 7, 1953 issue of ''Life'' presented ''The Age of Reptiles'' in reverse image (earliest to latest, left to right) of the mural order as a double-sided foldout page in which ''Edaphosaurus'' appeared in an Early Permian landscape with plants and animals of the period. The magazine series was edited into a popular book in 1955 that also had a foldout page for Zallinger's ''The Age of Reptiles'' artwork.
The Czech illustrator and paleoartist Zdeněk Burian
Zdeněk Michael František Burian (11 February 1905 in Kopřivnice, Moravia, Austria-Hungary – 1 July 1981 in Prague, Czechoslovakia) was a Czech painter, book illustrator and palaeoartist whose work played a central role in the development of p ...
created a number of vivid paintings of ''Edaphosaurus'' set in Paleozoic landscapes. (The choice to portray ''Edaphosaurus'' was based in part on edaphosaurid fossils found in native Carboniferous rocks in what is now the Czech Republic, originally identified as "''Naosaurus''" and now called ''Bohemiclavulus''.) These images appeared in the series of popular general audience books on prehistoric animals that Burian produced in collaboration with Czech paleontologists Josef Augusta and Zdeněk Špinar
Zdeněk Špinar (4 April 1916 – 14 August 1995) was a Czechoslovak paleontologist and author. He was renowned in the field for popularising vertebrate paleontology. He specialised in the paleontology of amphibians, especially anurans. Many o ...
beginning in the 1930s and on into the 1970s. Some of the books were translated into other languages, including English. Burian's painting from 1941 restored ''Edaphosaurus'' with a large carnivorous head and short tail, reflecting an outdated "''Naosaurus''" concept of the animal. The artwork was featured in Josef Augusta's ''Divy prasvěta'' (''Wonders of the Prehistoric World''), published during World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
in biweekly pamphlet form between 1941 and 1942, and then republished as a full book after the war. Burian subsequently corrected his 1941 ''Edaphosaurus'' reconstruction in a painting with the more accurate small head of a plant-eater and a long tail, the version of ''Edaphosaurus'' that appeared in later translated editions of Burian's books with Augusta such as ''Prehistoric Animals'' (1956). Another painting of ''Edaphosaurus'' by Burian appeared on the cover of the 1968 third edition of the juvenile popular science book ''Ztracený svět'' (''The Lost World''), also written by Augusta. The book ''Life Before Man'' (1972), written by Zdeněk Špinar, included an additional depiction of ''Edaphosaurus'' by Burian.[National Geographic: Permian Period: Photo Gallery]
Edaphosaurus
/ref>
See also
* ''Haptodus
''Haptodus'' is an extinct genus of basal sphenacodont, member of the clade that includes therapsids and hence, mammals. It was at least in length. It lived in present-day France during the Early Permian. It was a medium-sized predator, feeding ...
''
* '' Ianthasaurus''
* List of pelycosaurs
This list of pelycosaurs is an attempt to create a comprehensive listing of all genera that have ever been included in the synapsida excluding therapsida and purely vernacular terms. The list includes all commonly accepted genera, but also genera t ...
* ''Platyhystrix
''Platyhystrix'' (from el, πλατύς , 'flat' and el, ῠ̔́στρῐξ , 'porcupine') was a temnospondyl amphibian with a distinctive sail along its back, similar to the unrelated synapsids, ''Dimetrodon'' and ''Edaphosaurus''. It lived du ...
'' – an unrelated animal with a sail on its back
* ''Sphenacodon
''Sphenacodon'' (meaning "wedge point tooth") is an extinct genus of synapsid that lived from about 300 to about 280 million years ago (Ma) during the Late Carboniferous and Early Permian periods. Like the closely related '' Dimetrodon'', ''Sphen ...
''
* ''Dimetrodon
''Dimetrodon'' ( or ,) meaning "two measures of teeth,” is an extinct genus of non-mammalian synapsid that lived during the Cisuralian (Early Permian), around 295–272 million years ago (Mya). It is a member of the family Sphenacodontid ...
''
References
;Notes
;Bibliography
* Carroll, R. L. (1988), ''Vertebrate Paleontology and Evolution'', WH Freeman & Co.
* Colbert, E. H., (1969), ''Evolution of the Vertebrates'', John Wiley & Sons Inc (2nd ed.)
* Romer, A. S., (1947, revised ed. 1966) Vertebrate Paleontology, University of Chicago Press, Chicago
* Romer, A. S. and Price, L. I., (1940), ''Review of the Pelycosauria'', Geological Society of America Special Papers, No 28
External links
Edaphosauridae – edaphosaurs – (list of species)
{{Taxonbar, from=Q131688
Edaphosaurids
Prehistoric synapsid genera
Carboniferous synapsids
Cisuralian synapsids of Europe
Cisuralian synapsids of North America
Carboniferous United States
Permian United States
Taxa named by Edward Drinker Cope
Fossil taxa described in 1882
Pennsylvanian genus first appearances
Cisuralian genus extinctions