Bharattherium
Encyclopedia
Bharattherium is a mammal
that lived in India
during the Maastrichtian
(latest Cretaceous
). The genus
has a single species
, Bharattherium bonapartei. It is part of the gondwanathere
family Sudamericidae
, which is also found in Madagascar and South America during the latest Cretaceous. The first fossil of Bharattherium was discovered in 1989 and published in 1997, but the animal was not named until 2007, when two teams independently named the animal Bharattherium bonapartei and Dakshina jederi. The latter name is now a synonym
. Bharattherium is known from a total of eight isolated fossil teeth, including one incisor
and seven molariforms (molar
-like teeth, either premolars or true molars).
Bharattherium molariforms are high, curved teeth, with a height of 5.97 to 8.40 mm. In a number of teeth tentatively identified as fourth lower molariforms (mf4), there is a large furrow on one side and a deep cavity (infundibulum) in the middle of the tooth. Another tooth, perhaps a third lower molariform, has two furrows on one side and three infundibula on the other. The tooth enamel
has traits that have been interpreted as protecting against cracks in the teeth. The hypsodont
(high-crowned) teeth of sudamericids like Bharattherium is reminiscent of later grazing mammals, and the discovery of grass in Indian fossil sites contemporaneous with those yielding Bharattherium suggest that sudamericids were indeed grazers.
(latest Cretaceous
, about 70–66 million years ago) Intertrappean Beds
of Naskal, India, in 1989, but it was not identified as such until another gondwanathere, Lavanify
, was found on Madagascar in the middle 1990s. The discoveries of Lavanify and VPL/JU/NKIM/25 were announced in Nature
in 1997. Gondwanatheres were previously known only from Argentina; these discoveries extended the range of the gondwanathere family Sudamericidae
across the continents of the ancient supercontinent of Gondwana
.
In 2007, two teams of scientists independently named the Indian gondwanathere on the basis of new material; both teams included VPL/JU/NKIM/25 in their newly named species. Guntupalli Prasad and colleagues named the animal Bharattherium bonapartei on the basis of an additional tooth, VPL/JU/IM/33, from another Intertrappean locality, Kisalpuri. The generic name, Bharattherium, combines Bharat, Sanskrit
for "India", with the Ancient Greek
therion, meaning "beast", and the specific name, bonapartei, honors Argentinean paleontologist José Bonaparte
, who was the first to describe a gondwanathere fossil. G.P. Wilson and colleagues named Dakshina jederi on the basis of six teeth (in addition to VPL/JU/NKIM 25), and identified some additional material as indeterminate gondwanatheres. Of these teeth, three (GSI/SR/PAL-G059, G070, and G074) are from a third Intertrappean site at Gokak
and three (GSI/SR/PAL-N071, N210, and N212) are from Naskal. Dakshina, the generic name, derives from Sanskrit daakshinaatya "of the south", and refers both to the animal's occurrence in southern India and to the distribution of gondwanatheres in the southern continents. The specific name, jederi, honors University of Michigan
paleontologist Jeffrey A. Wilson
, nicknamed "Jeder", who played an important role in the project that led to the discovery of Dakshina. Wilson and colleagues also described three other gondwanathere teeth from Gokak (GSI/SR/PAL-G111, G112, and G211), which they tentatively identified as a different species of gondwanathere on their small size. In 2008, Prasad commented that Bharattherium bonapartei and Dakshina jederi represented the same species and that Bharattherium, which was published first, was the correct name.
Bharattherium bonapartei is known from a total of eight isolated teeth. Among the seven teeth in their sample, Wilson and colleagues tentatively identified five as fourth lower molariforms (mf4)—because gondwanathere premolar
s and molars
cannot be distinguished, they are collectively known as "molariforms"—one as a third lower molariform (mf3) and one as a lower incisor
(i1). These determinations were made on the basis of comparisons with a sample of the South American gondwanathere Sudamerica ameghinoi, in which all eight molariform positions are known. However, the large number of mf4s led Wilson and colleagues to suspect that the criteria used for distinguishing Sudamerica tooth positions may not apply directly to Bharattherium. Prasad and colleagues did not assign their two Bharattherium teeth to any tooth position, but suggested that they may represent different tooth positions and that one may come from the upper and the other from the lower side of the jaw. As is characteristic of sudamericids, Bharattherium molariforms are hypsodont
(high-crowned) and have a flat occlusal (chewing) surface atop a high tooth, with furrows that extend down the height of the tooth. Bharattherium molariforms are the smallest of any sudamericid; those of Lavanify, for example, are about 35% larger. Unlike Sudamerica molariforms, those of Bharattherium taper towards the top.
of Dakshina jederi, is 7.57 mm high and has a crown of 3.66 × 2.99 mm. It is curved, with the base more distal (towards the back) than the top. The occlusal surface is rectangular. On the lingual side (towards the tongue), there is a deep furrow (filled in part with cementum
) that extends from the top to near the base of the tooth. There is also a much smaller indentation on the buccal side (towards the cheeks). The occlusal surface is mostly covered with enamel
surrounding a dentine lake, but there is a V-shaped islet in the middle, with the tip of the V towards the lingual side, that forms the remnant of an infundibulum—a deep cavity in the tooth. Perikymata—wave-like bands and grooves—are visible in the enamel.
The right mf4 GSI/SR/PAL-G070, which is damaged on the buccal, distal, and lingual sides, is 8.40 mm high, but has an occlusal surface of only 2.49 × 1.75 mm. Unlike in GSI/SR/PAL-G074, the dentine on the occlusal surface is not exposed, and the occlusal surface is oval in shape. Furthermore, the V-shaped islet is larger and the lingual furrow is less prominent at the occlusal surface, because it tapers near the tip of the tooth. In the heavily damaged left mf4 GSI/SR/PAL-N071 (height 7.16 mm), only the distal side is well-preserved. The infundibulum is exposed internally; it extends 4.01 mm down the crown. The occlusal surface is poorly preserved, but its dimensions are at least 2.14 × 2.42 mm. GSI/SR/PAL-N212, a right mf4, is damaged on the mesial side and has a height of 5.86 mm and an occlusal surface of at least 2.66 x 2.04 mm. Cementum fills the V-shaped islet.
VPL/JU/NKIM/25 was the first Indian gondwanathere fossil to be described; it is damaged on one side. Wilson and colleagues identified it as a left mf4 (implying that the damaged side is buccal) with strong similarities to GSI/SR/PAL-G070, including a curved crown and a V-shaped enamel islet atop a deep infundibulum. The occlusal surface is oval. The tooth is 6 mm high and Wilson and colleagues estimate that the occlusal surface is 2.5 × 1.8 mm, close to the dimensions of GSI/SR/PAL-G070. They suggest the tooth probably had enamel on all sides of the crown, but Prasad and colleagues point to a possible enamel-dentine junction on the damaged side as evidence that enamel may be absent there.
GSI/SR/PAL-G059, identified as a left mf3, has a height of 5.97 mm at the mesial side, but only 2.02 mm at the distal side because of curvature. On the lingual side, two long furrows are visible, and on the buccal side breakage exposes three long infundibula, of which the most mesial one is the longest and the most distal one the shortest. In the occlusal surface, these three infundibula merge into a single islet. In addition, three dentine lakes are visible in the occlusal surface, which has dimensions of 4.58 × at least 2.52 mm. Although in Sudamerica, mf2, mf3, and the upper molariforms MF3 and MF4 all have three lophs, like GSI/SR/PAL-G059, its curvature matches the mf3 of Sudamerica best.
VPL/JU/IM/33, the holotype of Bharattherium bonapartei, is 7.33 mm high, 2.66 mm long, and 2.0 mm wide. The occlusal surface is about rectangular and is mostly covered by a V-shaped dentine lake, which encloses a small heart-shaped enamel islet at the top of an cementum-filled infundibulum. A vertical furrow is also present. Near the top of the tooth, enamel covers the entire crown, but further down there is no enamel on the concave face of the tooth.
(uniquely derived characters) of the Indian sudamericid.
; Gokak, Karnataka
; and Kisalpuri, Madhya Pradesh
. All sites are in the Intertrappean Beds
(part of the Deccan Traps
) and are Maastrichtian
(latest Cretaceous
) in age. The Intertrappean Beds have yielded a variety of fossil animals, including eutheria
n mammals such as Deccanolestes
, Sahnitherium
, and Kharmerungulatum
. In the perhaps slightly older Infratrappean Beds, a possible member of the ancient and enigmatic mammalian group Haramiyida
has been found, Avashishta. Members of the family Sudamericidae, in which Bharattherium is classified, are also known from the Cretaceous of Argentina, Madagascar, and possibly Tanzania and from the Paleogene
of Argentina and Antarctica, and the second gondwanathere family, Ferugliotheriidae
, is known with certainty only from the Cretaceous of Argentina. Thus, Bharattherium is an example of a Gondwana
n faunal element in India and indicates biogeographic
affinities with other Gondwanan landmasses such as Madagascar and South America.
In modern mammals, hypsodont teeth are often associated with diets that include abrasive vegetation like grasses. Hypsodonty in sudamericids has been interpreted as indicating semiaquatic, terrestrial habits and a diet with items like roots or bark, because it was thought that grasses had not yet appeared when sudamericids lived. However, grass remains have been found at Intertrappean sites contemporary with those where Bharattherium was found, suggesting that sudamericids like Bharattherium were indeed the first grazing mammals.
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
that lived in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
during the Maastrichtian
Maastrichtian
The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...
(latest Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
). The genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
has a single species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
, Bharattherium bonapartei. It is part of the gondwanathere
Gondwanatheria
Gondwanatheria is an extinct group of mammals that lived during the Upper Cretaceous through the Eocene in the Southern Hemisphere, including Antarctica...
family Sudamericidae
Sudamericidae
Sudamericidae is a family of gondwanathere mammals that lived during the late Cretaceous to Eocene. Its members include Lavanify from the Cretaceous of Madagascar, Bharattherium from the Cretaceous of India, Gondwanatherium from the Cretaceous of Argentina, Sudamerica from the Paleocene of...
, which is also found in Madagascar and South America during the latest Cretaceous. The first fossil of Bharattherium was discovered in 1989 and published in 1997, but the animal was not named until 2007, when two teams independently named the animal Bharattherium bonapartei and Dakshina jederi. The latter name is now a synonym
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
. Bharattherium is known from a total of eight isolated fossil teeth, including one incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
and seven molariforms (molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
-like teeth, either premolars or true molars).
Bharattherium molariforms are high, curved teeth, with a height of 5.97 to 8.40 mm. In a number of teeth tentatively identified as fourth lower molariforms (mf4), there is a large furrow on one side and a deep cavity (infundibulum) in the middle of the tooth. Another tooth, perhaps a third lower molariform, has two furrows on one side and three infundibula on the other. The tooth enamel
Tooth enamel
Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...
has traits that have been interpreted as protecting against cracks in the teeth. The hypsodont
Hypsodont
Hypsodont dentition is characterized by high-crowned teeth and enamel which extends past the gum line. This provides extra material for wear and tear. Some examples of animals with hypsodont dentition are cows, horses and deer; all animals that feed on gritty, fibrous material. The opposite...
(high-crowned) teeth of sudamericids like Bharattherium is reminiscent of later grazing mammals, and the discovery of grass in Indian fossil sites contemporaneous with those yielding Bharattherium suggest that sudamericids were indeed grazers.
Taxonomy
A gondwanathere tooth, catalogued as VPL/JU/NKIM/25, was first discovered in the MaastrichtianMaastrichtian
The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...
(latest Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
, about 70–66 million years ago) Intertrappean Beds
Intertrappean Beds
The Intertrappean Beds are a Late Cretaceous geologic formation in India. Indeterminate theropod and pterosaur remains have been recovered from the formation, as well as dinosaur eggs. The mammal genera Deccanolestes, Sahnitherium, Bharattherium , and Kharmerungulatum have been recovered from it as...
of Naskal, India, in 1989, but it was not identified as such until another gondwanathere, Lavanify
Lavanify
Lavanify is a mammalian genus from the late Cretaceous of Madagascar. The only species, L. miolaka, is known from two isolated teeth, one of which is damaged. The teeth were collected in 1995–1996 and described in 1997...
, was found on Madagascar in the middle 1990s. The discoveries of Lavanify and VPL/JU/NKIM/25 were announced in Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...
in 1997. Gondwanatheres were previously known only from Argentina; these discoveries extended the range of the gondwanathere family Sudamericidae
Sudamericidae
Sudamericidae is a family of gondwanathere mammals that lived during the late Cretaceous to Eocene. Its members include Lavanify from the Cretaceous of Madagascar, Bharattherium from the Cretaceous of India, Gondwanatherium from the Cretaceous of Argentina, Sudamerica from the Paleocene of...
across the continents of the ancient supercontinent of Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
.
In 2007, two teams of scientists independently named the Indian gondwanathere on the basis of new material; both teams included VPL/JU/NKIM/25 in their newly named species. Guntupalli Prasad and colleagues named the animal Bharattherium bonapartei on the basis of an additional tooth, VPL/JU/IM/33, from another Intertrappean locality, Kisalpuri. The generic name, Bharattherium, combines Bharat, Sanskrit
Sanskrit
Sanskrit , is a historical Indo-Aryan language and the primary liturgical language of Hinduism, Jainism and Buddhism.Buddhism: besides Pali, see Buddhist Hybrid Sanskrit Today, it is listed as one of the 22 scheduled languages of India and is an official language of the state of Uttarakhand...
for "India", with the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
therion, meaning "beast", and the specific name, bonapartei, honors Argentinean paleontologist José Bonaparte
José Bonaparte
José Fernando Bonaparte, Ph.D. , is an Argentine paleontologist who discovered a plethora of South American dinosaurs and mentored a new generation of Argentine paleontologists like Rodolfo Coria...
, who was the first to describe a gondwanathere fossil. G.P. Wilson and colleagues named Dakshina jederi on the basis of six teeth (in addition to VPL/JU/NKIM 25), and identified some additional material as indeterminate gondwanatheres. Of these teeth, three (GSI/SR/PAL-G059, G070, and G074) are from a third Intertrappean site at Gokak
Gokak
Gokak is a town and taluk headquarters in the Belgaum District of Karnataka state, India. It is located around 70 km from Belgaum at the confluence of two rivers, the Ghataprabha and the Markandeya. The population of the city is approximately 1,50,000 and the common language in use is Kannada...
and three (GSI/SR/PAL-N071, N210, and N212) are from Naskal. Dakshina, the generic name, derives from Sanskrit daakshinaatya "of the south", and refers both to the animal's occurrence in southern India and to the distribution of gondwanatheres in the southern continents. The specific name, jederi, honors University of Michigan
University of Michigan
The University of Michigan is a public research university located in Ann Arbor, Michigan in the United States. It is the state's oldest university and the flagship campus of the University of Michigan...
paleontologist Jeffrey A. Wilson
Jeffrey A. Wilson
Jeffrey A. Wilson also known as "JAW "is a professor of geological sciences and assistant curator at the Museum of Paleontology at the University of Michigan....
, nicknamed "Jeder", who played an important role in the project that led to the discovery of Dakshina. Wilson and colleagues also described three other gondwanathere teeth from Gokak (GSI/SR/PAL-G111, G112, and G211), which they tentatively identified as a different species of gondwanathere on their small size. In 2008, Prasad commented that Bharattherium bonapartei and Dakshina jederi represented the same species and that Bharattherium, which was published first, was the correct name.
Description
| Fossil | Locality | Tooth position | References |
|---|---|---|---|
| GSI/SR/PAL-G059 | Gokak | Left mf3 | |
| GSI/SR/PAL-G070 | Gokak | Right mf4 | |
| GSI/SR/PAL-G074 | Gokak | Right mf4 | |
| VPL/JU/IM/33 | Kisalpuri | Molariform | |
| GSI/SR/PAL-N071 | Naskal | Left mf4 | |
| GSI/SR/PAL-N210 | Naskal | Left i1 | |
| GSI/SR/PAL-N212 | Naskal | Right mf4 | |
| VPL/JU/NKIM/25 | Naskal | Left mf4 |
Bharattherium bonapartei is known from a total of eight isolated teeth. Among the seven teeth in their sample, Wilson and colleagues tentatively identified five as fourth lower molariforms (mf4)—because gondwanathere premolar
Premolar
The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered as a 'transitional tooth' during chewing, or...
s and molars
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
cannot be distinguished, they are collectively known as "molariforms"—one as a third lower molariform (mf3) and one as a lower incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
(i1). These determinations were made on the basis of comparisons with a sample of the South American gondwanathere Sudamerica ameghinoi, in which all eight molariform positions are known. However, the large number of mf4s led Wilson and colleagues to suspect that the criteria used for distinguishing Sudamerica tooth positions may not apply directly to Bharattherium. Prasad and colleagues did not assign their two Bharattherium teeth to any tooth position, but suggested that they may represent different tooth positions and that one may come from the upper and the other from the lower side of the jaw. As is characteristic of sudamericids, Bharattherium molariforms are hypsodont
Hypsodont
Hypsodont dentition is characterized by high-crowned teeth and enamel which extends past the gum line. This provides extra material for wear and tear. Some examples of animals with hypsodont dentition are cows, horses and deer; all animals that feed on gritty, fibrous material. The opposite...
(high-crowned) and have a flat occlusal (chewing) surface atop a high tooth, with furrows that extend down the height of the tooth. Bharattherium molariforms are the smallest of any sudamericid; those of Lavanify, for example, are about 35% larger. Unlike Sudamerica molariforms, those of Bharattherium taper towards the top.
Molariforms
GSI/SR/PAL-G074, a well-preserved right mf4 that Wilson and colleagues selected as the holotypeHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
of Dakshina jederi, is 7.57 mm high and has a crown of 3.66 × 2.99 mm. It is curved, with the base more distal (towards the back) than the top. The occlusal surface is rectangular. On the lingual side (towards the tongue), there is a deep furrow (filled in part with cementum
Cementum
Cementum is a specialized calcified substance covering the root of a tooth. Cementum is excreted by cells called cementoblasts within the root of the tooth and is thickest at the root apex. These cementoblasts develop from undifferentiated mesenchymal cells in the connective tissue of the dental...
) that extends from the top to near the base of the tooth. There is also a much smaller indentation on the buccal side (towards the cheeks). The occlusal surface is mostly covered with enamel
Tooth enamel
Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...
surrounding a dentine lake, but there is a V-shaped islet in the middle, with the tip of the V towards the lingual side, that forms the remnant of an infundibulum—a deep cavity in the tooth. Perikymata—wave-like bands and grooves—are visible in the enamel.
The right mf4 GSI/SR/PAL-G070, which is damaged on the buccal, distal, and lingual sides, is 8.40 mm high, but has an occlusal surface of only 2.49 × 1.75 mm. Unlike in GSI/SR/PAL-G074, the dentine on the occlusal surface is not exposed, and the occlusal surface is oval in shape. Furthermore, the V-shaped islet is larger and the lingual furrow is less prominent at the occlusal surface, because it tapers near the tip of the tooth. In the heavily damaged left mf4 GSI/SR/PAL-N071 (height 7.16 mm), only the distal side is well-preserved. The infundibulum is exposed internally; it extends 4.01 mm down the crown. The occlusal surface is poorly preserved, but its dimensions are at least 2.14 × 2.42 mm. GSI/SR/PAL-N212, a right mf4, is damaged on the mesial side and has a height of 5.86 mm and an occlusal surface of at least 2.66 x 2.04 mm. Cementum fills the V-shaped islet.
VPL/JU/NKIM/25 was the first Indian gondwanathere fossil to be described; it is damaged on one side. Wilson and colleagues identified it as a left mf4 (implying that the damaged side is buccal) with strong similarities to GSI/SR/PAL-G070, including a curved crown and a V-shaped enamel islet atop a deep infundibulum. The occlusal surface is oval. The tooth is 6 mm high and Wilson and colleagues estimate that the occlusal surface is 2.5 × 1.8 mm, close to the dimensions of GSI/SR/PAL-G070. They suggest the tooth probably had enamel on all sides of the crown, but Prasad and colleagues point to a possible enamel-dentine junction on the damaged side as evidence that enamel may be absent there.
GSI/SR/PAL-G059, identified as a left mf3, has a height of 5.97 mm at the mesial side, but only 2.02 mm at the distal side because of curvature. On the lingual side, two long furrows are visible, and on the buccal side breakage exposes three long infundibula, of which the most mesial one is the longest and the most distal one the shortest. In the occlusal surface, these three infundibula merge into a single islet. In addition, three dentine lakes are visible in the occlusal surface, which has dimensions of 4.58 × at least 2.52 mm. Although in Sudamerica, mf2, mf3, and the upper molariforms MF3 and MF4 all have three lophs, like GSI/SR/PAL-G059, its curvature matches the mf3 of Sudamerica best.
VPL/JU/IM/33, the holotype of Bharattherium bonapartei, is 7.33 mm high, 2.66 mm long, and 2.0 mm wide. The occlusal surface is about rectangular and is mostly covered by a V-shaped dentine lake, which encloses a small heart-shaped enamel islet at the top of an cementum-filled infundibulum. A vertical furrow is also present. Near the top of the tooth, enamel covers the entire crown, but further down there is no enamel on the concave face of the tooth.
Incisor
The left i1 GSI/SR/PAL-N210 is flat on the medial side (towards the middle of the head) but convex on the lateral side (towards the side of the head) and bears a shallow groove on the lateral side. At the base, the tooth is broadest on the lower end. The tooth is slightly curved upward towards the tip. Measured on the lower side, the tooth is 11.76 mm long, but breakage means the true length is probably larger. The depth of the tooth is about 3.39 mm. Wilson and colleagues identified this incisor as Dakshina on the basis of its size; the upper and lower incisor that they assigned to an indeterminate gondwanathere are smaller.Enamel microstructure
The microstructure of the enamel of VPL/JU/NKIM/25 has been studied. Unlike other gondwanatheres, it has enamel consisting of three layers—radial enamel, tangential enamel, and PLEX. The rows of small, round enamel prisms are separated by interprismatic matrix that forms crystalls oriented at right angles relative to the prisms. Prisms arise at the enamel-dentine junction, run through the enamel, and meet the outer enamel at a high angle. These features of the enamel are apparently adaptations that protect the tooth from cracks.Relationships
Bharattherium is identifiable as a sudamericid because it has hypsodont molariforms with cementum-filled furrows. Among the four known sudamericid genera—Gondwanatherium and Sudamerica from Argentina; Lavanify from Madagascar; and Bharattherium—it shares with Sudamerica and Lavanify the presence of furrows that extend down to the base of the tooth. In addition, it shares several features with Lavanify, suggesting the two are closely related. Wilson and colleagues list three features shared by the two: the presence of an infundibulum (seen in only one of two specimens of Lavanify), interprismatic matrix, and perikymata. Prasad and colleagues also interpreted the interprismatic matrix as a shared character, but added the absence of enamel on one side of the tooth crown. Wilson and colleagues identified the presence of a V-shaped enamel lake on mf4 and of three layers in the enamel as autapmorphiesAutapomorphy
In cladistics, an autapomorphy is a distinctive anatomical feature, known as a derived trait, that is unique to a given terminal group. That is, it is found only in one member of a clade, but not found in any others or outgroup taxa, not even those most closely related to the group...
(uniquely derived characters) of the Indian sudamericid.
Range and ecology
Remains of Bharattherium have been found at three widely separated Late Cretaceous sites in peninsular India—Naskal, Andhra PradeshAndhra Pradesh
Andhra Pradesh , is one of the 28 states of India, situated on the southeastern coast of India. It is India's fourth largest state by area and fifth largest by population. Its capital and largest city by population is Hyderabad.The total GDP of Andhra Pradesh is $100 billion and is ranked third...
; Gokak, Karnataka
Karnataka
Karnataka , the land of the Kannadigas, is a state in South West India. It was created on 1 November 1956, with the passing of the States Reorganisation Act and this day is annually celebrated as Karnataka Rajyotsava...
; and Kisalpuri, Madhya Pradesh
Madhya Pradesh
Madhya Pradesh , often called the Heart of India, is a state in central India. Its capital is Bhopal and Indore is the largest city....
. All sites are in the Intertrappean Beds
Intertrappean Beds
The Intertrappean Beds are a Late Cretaceous geologic formation in India. Indeterminate theropod and pterosaur remains have been recovered from the formation, as well as dinosaur eggs. The mammal genera Deccanolestes, Sahnitherium, Bharattherium , and Kharmerungulatum have been recovered from it as...
(part of the Deccan Traps
Deccan Traps
The Deccan Traps are a large igneous province located on the Deccan Plateau of west-central India and one of the largest volcanic features on Earth. They consist of multiple layers of solidified flood basalt that together are more than thick and cover an area of and a volume of...
) and are Maastrichtian
Maastrichtian
The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...
(latest Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
) in age. The Intertrappean Beds have yielded a variety of fossil animals, including eutheria
Eutheria
Eutheria is a group of mammals consisting of placental mammals plus all extinct mammals that are more closely related to living placentals than to living marsupials . They are distinguished from noneutherians by various features of the feet, ankles, jaws and teeth...
n mammals such as Deccanolestes
Deccanolestes
Deccanolestes is a scansorial, basal Euarchontan from the Late Cretaceous Intertrappean Beds of Andhra Pradesh, India. It may be closely related to Sahnitherium...
, Sahnitherium
Sahnitherium
Sahnitherium is a possible basal Euarchontan from the Maastrichtian of the Intertrappean Beds of Andhra Pradesh, India. It may be closely related to Deccanolestes. The holotype is an upper molar, and it is the only specimen of Sahnitherium....
, and Kharmerungulatum
Kharmerungulatum
Kharmerungulatum is an extinct genus of Condylarth from the Late Cretaceous Intertrappean Beds of Andhra Pradesh, India. Its specific epithet honors Leigh Van Valen. It is considered to be one of the earliest known condylarths....
. In the perhaps slightly older Infratrappean Beds, a possible member of the ancient and enigmatic mammalian group Haramiyida
Haramiyida
Haramiyidans seem to be the earliest known herbivores amongst basal mammals, assuming they are mammals. Their teeth, which are by far the most common remains, resemble those of the multituberculates...
has been found, Avashishta. Members of the family Sudamericidae, in which Bharattherium is classified, are also known from the Cretaceous of Argentina, Madagascar, and possibly Tanzania and from the Paleogene
Paleogene
The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...
of Argentina and Antarctica, and the second gondwanathere family, Ferugliotheriidae
Ferugliotheriidae
Ferugliotheriidae is one of two known families in the order Gondwanatheria, an enigmatic group of extinct mammals. Gondwanatheres have been classified as a group of uncertain affinities or as members of Multituberculata, a major extinct mammalian order. The best-known representative of...
, is known with certainty only from the Cretaceous of Argentina. Thus, Bharattherium is an example of a Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
n faunal element in India and indicates biogeographic
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
affinities with other Gondwanan landmasses such as Madagascar and South America.
In modern mammals, hypsodont teeth are often associated with diets that include abrasive vegetation like grasses. Hypsodonty in sudamericids has been interpreted as indicating semiaquatic, terrestrial habits and a diet with items like roots or bark, because it was thought that grasses had not yet appeared when sudamericids lived. However, grass remains have been found at Intertrappean sites contemporary with those where Bharattherium was found, suggesting that sudamericids like Bharattherium were indeed the first grazing mammals.