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Insular India
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Across the latter stages of the [[Cretaceous]] and most of the [[Paleocene]], the [[Indian subcontinent]] remained an isolated landmass as it drifted across the [[Tethys Ocean]], forming the [[Indian Ocean]]. The process of India's separation from [[Madagascar]] first began 88 million years ago, but complete isolation only occurred towards the end of the [[Maastrichtian]], a process that has been suggested to be the creation of the [[Deccan Traps]]. Soon after, the land mass moved northward rather quickly, until contact with [[Asia]] was established 55 million years ago. Even then, both landmasses didn't become fully united until around 35 million years ago,<ref>Scotese, Christopher R. (January 2001). "The collision of India and Asia (90 mya — present)". Paleomap Project. Retrieved 28 December 2004.</ref><ref>Aitchison, Jonathan C.; Ali, Jason R.; Davis, Aileen M. (2007). "When and where did India and Asia collide?". Journal of Geophysical Research. 112 (B5). Bibcode:2007JGRB..11205423A. </ref> and periods of isolation occured as recently as 24 million years ago.<ref>Biotic interchange between the Indian subcontinent and mainland Asia through time. Nat Commun. 2016 Jul 4;7:12132. doi: 10.1038/ncomms12132.</ref>
Thus, for a period of 53 million years India has retained a degree of isolation, 11 of which it has been a complete island continent. This has allowed for its local biota to follow the typical patterns seen in islands and diversify in unique ways, much like in modern Madagascar, its sister landmass. Most interestingly, faunal interchanges with other landmasses, like [[Africa]] and [[Europe]] (then an archipelago of islands across the Tethys) have occured during this period, and a considerable [[Asian]] influence can already been seen long before contact was made. This rendered India rather peculiar as not just an isolated continent but also a "stepping stone" in the dispersal of many animal and plant clades across Africa, Europe, Madagascar, Asia and possibly even [[Oceania]]. Still, several "archaic" clades managed to survive.
By the time full contact was established, a large percentage of India's indigenous fauna was outcompeted by Eurasian species. However, several groups like [[neobatrachia]]ns<ref>Zhang, Peng; Zhou, Hui; Chen, Yue-Qin; Liu, Yi-Fei; Qu, Liang-Hu (2005). "Mitogenomic perspectives on the origin and phylogeny of living amphibians". Systematic Biology. 54 (3): 391–400. doi:10.1080/10635150590945278. PMID 16012106.</ref> and [[lagomorph]]s<ref>Rose K.D., Deleon V.B., Mmissian P., Rana R.S., Sahni A., Singh L. & Smith T. (2008). – Early Eocene lagomorph (Mammalia) from western India and the early diversification of Lagomorpha. – Proc. Royal Society B, RSPB 2007.1661.R1</ref> have become widespread, becoming dominant clades across the world's faunas. The islands of the [[Seychelles]] still retain an indigenous [[herpetofauna]], presumably a echo of the [[amphibian]] and [[reptile]] species seen in India as an island.
==Cretaceous Fauna==
The Cretaceous fauna of India is well attested in both [[Coniacian]] and [[Maastrichtian]] aged sites such as the [[Lameta Formation]]. Generally speaking, the local [[dinosaurian]] and [[crocodilian]] fauna is almost identical to that of [[Madagascar]], with clades like [[abelisaurids]], [[titanosaurs]], [[noasaurids]] and [[notosuchians]] being well represented here. A possible deviation is the presence of [[stegosaurus]], the last remaining members of this lineage;<ref>Peter M. Galton; Krishnan Ayyasami (2017). "Purported latest bone of a plated dinosaur (Ornithischia: Stegosauria), a "dermal plate" from the Maastrichtian (Upper Cretaceous) of southern India". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 285 (1): 91–96. doi:10.1127/njgpa/2017/0671.</ref> if these aren't misidentified remains of herbivorous notosuchians and sauropods, then these relics would be the only indigenous [[ornithischians]] in the entire Indo-Malagasy landmass. Another possible deviation is the presence of a [[troodontid]],<ref>A troodontid dinosaur from the latest Cretaceous of India, Nature Communications volume 4, Article number: 1703 (2013)
doi:10.1038/ncomms2716,Received:
14 December 2012
Accepted:
07 March 2013
Published:
16 April 2013</ref>, a lineage more typically associated with [[Laurasia]] and thus possibly indicating interchange with [[Europe]] or even mainland [[Asia]], but these remains are controversial and could belong either other theropods or notosuchians.
The mammalian fauna of India also bears similarities with that of Madagascar, with the [[gondwanathere]] ''[[Bharattherium]]'', one of the most common mammals, being extremely similar to the malagasy ''[[Lavanify]]''. The most diverse mammals in the [[Maastrichtian]] of India are [[eutherians]], a clade normally associated with northern continents [[UA 8699|and also found in Madagascar in this epoch]], which combined with their ambiguous phylogenetic positions renders them extremely important in the understanding of [[placental]] evolution. Some like ''[[Deccanolestes]]'' have been variously interpreted as [[euarchonta]]ns,<ref>Boyer, Doug M.; Prasad, Guntupalli V. R.; Krause, David W.; Godinot, Marc; Goswami, Anjali; Verma, Omkar; Flynn, John J. (2010). "New postcrania of Deccanolestes from the Late Cretaceous of India and their bearing on the evolutionary and biogeographic history of euarchontan mammals". Naturwissenschaften. 97 (4): 365–77. doi:10.1007/s00114-010-0648-0. PMID 20130827.</ref>, [[adapisoriculid]]s,<ref>Smith, Thierry; Bast, Eric; Sigé, Bernard (2010). "Euarchontan affinity of Paleocene Afro-European adapisoriculid mammals and their origin in the late Cretaceous Deccan Traps of India". Naturwissenschaften. 97 (4): 417–22. doi:10.1007/s00114-010-0651-5. PMID 20174778.</ref> or stem-[[afrotherian]]s,<ref>Erik R. Seiffert, The Oldest and Youngest Records of Afrosoricid Placentals from the Fayum Depression of Northern Egypt</ref>, though the general consensus appears to be that they are non-placental eutherians and that there are non known Cretaceous [[placental]]s.<ref>Halliday, Thomas J. D. (2015). "Resolving the relationships of Paleocene placental mammals". Biological Reviews. doi:10.1111/brv.12242.</ref> ''[[Kharmerungulatum]]'', formerly interpreted as a stem-[[ungulate]], is now known to be a representative of [[Zhesletidae]], a herbivorous non-placental eutherian clade.<ref>James David Archibald · Alexander Olegovich Averianov, Phylogenetic analysis, taxonomic revision, and dental ontogeny of the Cretaceous Zhelestidae (Mammalia: Eutheria), Article · Feb 2012 · Zoological Journal of the Linnean Society</ref>. Regardless of the phylogenetics of these eutherians, they almost certainly reached India and Madagascar through either Europe, Africa or mainland Asia;<ref>Krause, D.W., O'Connor, P.M., Rogers, K.C., Sampson, S.D., Buckley, G.A. and Rogers, R.R. 2006. Late Cretaceous terrestrial vertebrates from Madagascar: Implications for Latin American biogeography (subscription required). Annals of the Missouri Botanical Garden 93(2):178–208.</ref><ref>Erik R. Seiffert, The Oldest and Youngest Records of Afrosoricid Placentals from the Fayum Depression of Northern Egypt</ref> later they would propagate across [[Gondwana]] as far west as [[Brazil]].<ref>https://ift.tt/2HzdZXr>
Probably the most spectacular representative of India's Cretaceous fauna is ''[[Avashishta]]'', a late surviving [[haramiyid]] and the last known non-mammalian [[synapsid]].<ref>Anantharaman, S.; Wilson, G. P.; Das Sarma, D. C.; Clemens, W. A. (2006). "A possible Late Cretaceous "haramiyidan" from India". Journal of Vertebrate Paleontology. 26 (2): 488–490. doi:10.1671/0272-4634(2006)26[488:aplchf]2.0.co;2.</ref> Non-gondwanathere [[multituberculates]] and [[meridiolestida]]ns can probably also be inferred as having lived in India during this epoch, due to the former's presence in all landmasses including Madagascar<ref>David W. Krause; Simone Hoffmann; Sarah Werning (2017). "First postcranial remains of Multituberculata (Allotheria, Mammalia) from Gondwana". Cretaceous Research. 80: 91–100. doi:10.1016/j.cretres.2017.08.009.</ref> and the latter being the dominant mammals in other known [[Gondwannan]] sites.
The [[herpetofauna]] of India in the Cretaceous is a mosaic of indigenous groups and forms that rafted their way from Asia. [[Neobatrachians]] are an indigenous clade and locally well represented as they are in Madagascar in the form of [[ranids]], [[hylids]], [[leptodactylids]], [[pelobatids]] and [[discoglossids]], as are [[madtsoiid]] [[snakes]] like ''[[Sanajeh]]'' and possibly ''[[Indophis]]'' and [[iguanian]] lizards, while [[anguids]] are from [[Laurasia]].<ref>Indian Cretaceous Terrestrial Vertebrates: Cosmopolitanism and Endemism in a Geodynamic Plate Tectonic Framework January 1970Lecture Notes in Earth Sciences 132:91-104
DOI: 10.1007/978-3-642-10311-7_6
In book: New Aspects of Mesozoic Biodiversity</ref>
Several fish taxa are known from estuarine locales; most are marine species, but there are also forms like [[lepisosteids]], which do also occur in [[Africa]] but are otherwise rare in gondwannan landmasses.<ref>Indian Cretaceous Terrestrial Vertebrates: Cosmopolitanism and Endemism in a Geodynamic Plate Tectonic Framework January 1970Lecture Notes in Earth Sciences 132:91-104
DOI: 10.1007/978-3-642-10311-7_6
In book: New Aspects of Mesozoic Biodiversity</ref> [[Cichlids]] and other forms suspected of having had an indian gondwannan origion were most likely present.
==Paleocene Fauna==
The fossil record of the Paleocene of India, when the continent was a fully isolated landmass, is rather sketchy and thus most inferrals about its fauna are somewhat speculative. It is known for certain that ''[[Deccanolestes]]'' and ''[[Bharattherium]]'' survived the KT event,<ref> WILSON, Gregory P, NEW MAMMALIAN FOSSILS FROM THE INTERTRAPPEAN BEDS OF THE SOUTHERN PART OF THE DECCAN VOLCANIC PROVINCE AND THE CRETACEOUS–PALEOGENE TRANSITION IN INDIA, October 27, 2016</ref> though for how further long did non-placental eutherians and gondwanatheres live in India is unknown, and by the time the landmass makes contact with Asia they are most likely extinct.
During this epoch, unambiguous placental mammals make their way into India in spite of its isolation, probably by rafting like the many placental groups in Madagascar, or perhaps brief connections with Africa and Europe (the latter still an archipelago). [[Hyaenodonts]] are an endemic african clade, first showing outside of the continent in the Paleocene of India and Europe,<ref>Floréal Solé & Thierry Smith, Dispersals of placental carnivorous mammals (Carnivoramorpha, Oxyaenodonta & Hyaenodontida) near the Paleocene-Eocene boundary: a climatic and almost worldwide story, GEOLOGICA BELGICA (2013) 16/4: 254-261</ref>. [[Glires]] evolved in Asia, but a lineage became isolated in India, where it gave rise to the lagomorphs.<ref>Rose K.D., Deleon V.B., Mmissian P., Rana R.S., Sahni A., Singh L. & Smith T. (2008). – Early Eocene lagomorph (Mammalia) from western India and the early diversification of Lagomorpha. – Proc. Royal Society B, RSPB 2007.1661.R1</ref>
For a while it was theorised that [[ostriches]] evolved in India during this epoch, under the assumption that european ratites like ''[[Palaeotis]]'' represented recent asiatic migrations. However, the first unambiguous ostriches are now thought to have evolved in Africa, with [[Eogruiidae|eogruiids]] having occupied their ecological niche in Asia; likewise, european ratites are now thought to be among the oldest known,<ref>Buffetaut, E.; Angst, D. (November 2014). "Stratigraphic distribution of large flightless birds in the Palaeogene of Europe and its palaeobiological and palaeogeographical implications". Earth-Science Reviews. 138: 394–408. doi:10.1016/j.earscirev.2014.07.001.</ref> and probably evolved independently there, being unrelated to ostriches. Still, India probably had a thriving [[paleognath]] fauna; the volant ancestors of [[kiwis]] and [[elephant birds]] presumably flew from there to Oceania and Madagascar respectively,<ref>Mitchell, K. J.; Llamas, B.; Soubrier, J.; Rawlence, N. J.; Worthy, T. H.; Wood, J.; Lee, M. S. Y.; Cooper, A. (2014-05-23). "Ancient DNA reveals elephant birds and kiwi are sister taxa and clarifies ratite bird evolution". Science. 344 (6186): 898–900. doi:10.1126/science.1251981. PMID 24855267.</ref> while the mysterious ''[[Hypselornis]]'' may represent an indigenous clade.
[[Caecillians]] are an indigenous gondwannan clade, but their absence in Madagascar suggests that the asian species have descended from african species that colonized India as it drifted north.<ref>Phylogenetic relationships of Indian caecilians (Amphibia:
Gymnophiona) inferred from mitochondrial rRNA gene sequences, Department of Zoology, The Natural History Museum, London SW7 5BD, UK b Institute of Biomedical and Life Sciences, Division of Molecular Genetics, University of Glasgow, Pontecorvo Building, 56 Dumbarton Rd,
Glasgow G11 6NU, Scotland, UK c Department of Zoology, University of Kerala, Kariavattom 695 581, Thiruvananthapuram, Kerala, India
Received 27 June 2001; received in revised form 17 December 2001</ref>
==Eocene Fauna==
By this time India already has an extensive placental fauna (as well as [[metatherians]] like ''[[Indodelphis]]''), but in its isolation there are still high degrees of endemism, with some clades like [[anthracobunids]] not being found elsewhere. The most notorious endemic mammals are [[cetaceans]], which are in fact restricted to the Indian Subcontinent until the evolution of the marine "[[protocetids]]". Eocene India is also rich in [[bat]] remains, including many representatives of modern groups, though its unclear if this indian chiropteran fauna represents an adaptive radiation or simply that bat fossils elsewhere are rare.<ref>Eiting, T.P.; Gunnell, G.F. (2009). "Global completeness of the bat fossil record". Journal of Mammalian Evolution. 16: 151–173. doi:10.1007/s10914-009-9118-x.</ref>
During this time [[ranids]], [[lagomorphs]] and [[hyaenodonts]] disperse out of India, establishing their cosmopolitan ranges.
==References==
[[Category:Historical continents]]
Thus, for a period of 53 million years India has retained a degree of isolation, 11 of which it has been a complete island continent. This has allowed for its local biota to follow the typical patterns seen in islands and diversify in unique ways, much like in modern Madagascar, its sister landmass. Most interestingly, faunal interchanges with other landmasses, like [[Africa]] and [[Europe]] (then an archipelago of islands across the Tethys) have occured during this period, and a considerable [[Asian]] influence can already been seen long before contact was made. This rendered India rather peculiar as not just an isolated continent but also a "stepping stone" in the dispersal of many animal and plant clades across Africa, Europe, Madagascar, Asia and possibly even [[Oceania]]. Still, several "archaic" clades managed to survive.
By the time full contact was established, a large percentage of India's indigenous fauna was outcompeted by Eurasian species. However, several groups like [[neobatrachia]]ns<ref>Zhang, Peng; Zhou, Hui; Chen, Yue-Qin; Liu, Yi-Fei; Qu, Liang-Hu (2005). "Mitogenomic perspectives on the origin and phylogeny of living amphibians". Systematic Biology. 54 (3): 391–400. doi:10.1080/10635150590945278. PMID 16012106.</ref> and [[lagomorph]]s<ref>Rose K.D., Deleon V.B., Mmissian P., Rana R.S., Sahni A., Singh L. & Smith T. (2008). – Early Eocene lagomorph (Mammalia) from western India and the early diversification of Lagomorpha. – Proc. Royal Society B, RSPB 2007.1661.R1</ref> have become widespread, becoming dominant clades across the world's faunas. The islands of the [[Seychelles]] still retain an indigenous [[herpetofauna]], presumably a echo of the [[amphibian]] and [[reptile]] species seen in India as an island.
==Cretaceous Fauna==
The Cretaceous fauna of India is well attested in both [[Coniacian]] and [[Maastrichtian]] aged sites such as the [[Lameta Formation]]. Generally speaking, the local [[dinosaurian]] and [[crocodilian]] fauna is almost identical to that of [[Madagascar]], with clades like [[abelisaurids]], [[titanosaurs]], [[noasaurids]] and [[notosuchians]] being well represented here. A possible deviation is the presence of [[stegosaurus]], the last remaining members of this lineage;<ref>Peter M. Galton; Krishnan Ayyasami (2017). "Purported latest bone of a plated dinosaur (Ornithischia: Stegosauria), a "dermal plate" from the Maastrichtian (Upper Cretaceous) of southern India". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 285 (1): 91–96. doi:10.1127/njgpa/2017/0671.</ref> if these aren't misidentified remains of herbivorous notosuchians and sauropods, then these relics would be the only indigenous [[ornithischians]] in the entire Indo-Malagasy landmass. Another possible deviation is the presence of a [[troodontid]],<ref>A troodontid dinosaur from the latest Cretaceous of India, Nature Communications volume 4, Article number: 1703 (2013)
doi:10.1038/ncomms2716,Received:
14 December 2012
Accepted:
07 March 2013
Published:
16 April 2013</ref>, a lineage more typically associated with [[Laurasia]] and thus possibly indicating interchange with [[Europe]] or even mainland [[Asia]], but these remains are controversial and could belong either other theropods or notosuchians.
The mammalian fauna of India also bears similarities with that of Madagascar, with the [[gondwanathere]] ''[[Bharattherium]]'', one of the most common mammals, being extremely similar to the malagasy ''[[Lavanify]]''. The most diverse mammals in the [[Maastrichtian]] of India are [[eutherians]], a clade normally associated with northern continents [[UA 8699|and also found in Madagascar in this epoch]], which combined with their ambiguous phylogenetic positions renders them extremely important in the understanding of [[placental]] evolution. Some like ''[[Deccanolestes]]'' have been variously interpreted as [[euarchonta]]ns,<ref>Boyer, Doug M.; Prasad, Guntupalli V. R.; Krause, David W.; Godinot, Marc; Goswami, Anjali; Verma, Omkar; Flynn, John J. (2010). "New postcrania of Deccanolestes from the Late Cretaceous of India and their bearing on the evolutionary and biogeographic history of euarchontan mammals". Naturwissenschaften. 97 (4): 365–77. doi:10.1007/s00114-010-0648-0. PMID 20130827.</ref>, [[adapisoriculid]]s,<ref>Smith, Thierry; Bast, Eric; Sigé, Bernard (2010). "Euarchontan affinity of Paleocene Afro-European adapisoriculid mammals and their origin in the late Cretaceous Deccan Traps of India". Naturwissenschaften. 97 (4): 417–22. doi:10.1007/s00114-010-0651-5. PMID 20174778.</ref> or stem-[[afrotherian]]s,<ref>Erik R. Seiffert, The Oldest and Youngest Records of Afrosoricid Placentals from the Fayum Depression of Northern Egypt</ref>, though the general consensus appears to be that they are non-placental eutherians and that there are non known Cretaceous [[placental]]s.<ref>Halliday, Thomas J. D. (2015). "Resolving the relationships of Paleocene placental mammals". Biological Reviews. doi:10.1111/brv.12242.</ref> ''[[Kharmerungulatum]]'', formerly interpreted as a stem-[[ungulate]], is now known to be a representative of [[Zhesletidae]], a herbivorous non-placental eutherian clade.<ref>James David Archibald · Alexander Olegovich Averianov, Phylogenetic analysis, taxonomic revision, and dental ontogeny of the Cretaceous Zhelestidae (Mammalia: Eutheria), Article · Feb 2012 · Zoological Journal of the Linnean Society</ref>. Regardless of the phylogenetics of these eutherians, they almost certainly reached India and Madagascar through either Europe, Africa or mainland Asia;<ref>Krause, D.W., O'Connor, P.M., Rogers, K.C., Sampson, S.D., Buckley, G.A. and Rogers, R.R. 2006. Late Cretaceous terrestrial vertebrates from Madagascar: Implications for Latin American biogeography (subscription required). Annals of the Missouri Botanical Garden 93(2):178–208.</ref><ref>Erik R. Seiffert, The Oldest and Youngest Records of Afrosoricid Placentals from the Fayum Depression of Northern Egypt</ref> later they would propagate across [[Gondwana]] as far west as [[Brazil]].<ref>https://ift.tt/2HzdZXr>
Probably the most spectacular representative of India's Cretaceous fauna is ''[[Avashishta]]'', a late surviving [[haramiyid]] and the last known non-mammalian [[synapsid]].<ref>Anantharaman, S.; Wilson, G. P.; Das Sarma, D. C.; Clemens, W. A. (2006). "A possible Late Cretaceous "haramiyidan" from India". Journal of Vertebrate Paleontology. 26 (2): 488–490. doi:10.1671/0272-4634(2006)26[488:aplchf]2.0.co;2.</ref> Non-gondwanathere [[multituberculates]] and [[meridiolestida]]ns can probably also be inferred as having lived in India during this epoch, due to the former's presence in all landmasses including Madagascar<ref>David W. Krause; Simone Hoffmann; Sarah Werning (2017). "First postcranial remains of Multituberculata (Allotheria, Mammalia) from Gondwana". Cretaceous Research. 80: 91–100. doi:10.1016/j.cretres.2017.08.009.</ref> and the latter being the dominant mammals in other known [[Gondwannan]] sites.
The [[herpetofauna]] of India in the Cretaceous is a mosaic of indigenous groups and forms that rafted their way from Asia. [[Neobatrachians]] are an indigenous clade and locally well represented as they are in Madagascar in the form of [[ranids]], [[hylids]], [[leptodactylids]], [[pelobatids]] and [[discoglossids]], as are [[madtsoiid]] [[snakes]] like ''[[Sanajeh]]'' and possibly ''[[Indophis]]'' and [[iguanian]] lizards, while [[anguids]] are from [[Laurasia]].<ref>Indian Cretaceous Terrestrial Vertebrates: Cosmopolitanism and Endemism in a Geodynamic Plate Tectonic Framework January 1970Lecture Notes in Earth Sciences 132:91-104
DOI: 10.1007/978-3-642-10311-7_6
In book: New Aspects of Mesozoic Biodiversity</ref>
Several fish taxa are known from estuarine locales; most are marine species, but there are also forms like [[lepisosteids]], which do also occur in [[Africa]] but are otherwise rare in gondwannan landmasses.<ref>Indian Cretaceous Terrestrial Vertebrates: Cosmopolitanism and Endemism in a Geodynamic Plate Tectonic Framework January 1970Lecture Notes in Earth Sciences 132:91-104
DOI: 10.1007/978-3-642-10311-7_6
In book: New Aspects of Mesozoic Biodiversity</ref> [[Cichlids]] and other forms suspected of having had an indian gondwannan origion were most likely present.
==Paleocene Fauna==
The fossil record of the Paleocene of India, when the continent was a fully isolated landmass, is rather sketchy and thus most inferrals about its fauna are somewhat speculative. It is known for certain that ''[[Deccanolestes]]'' and ''[[Bharattherium]]'' survived the KT event,<ref> WILSON, Gregory P, NEW MAMMALIAN FOSSILS FROM THE INTERTRAPPEAN BEDS OF THE SOUTHERN PART OF THE DECCAN VOLCANIC PROVINCE AND THE CRETACEOUS–PALEOGENE TRANSITION IN INDIA, October 27, 2016</ref> though for how further long did non-placental eutherians and gondwanatheres live in India is unknown, and by the time the landmass makes contact with Asia they are most likely extinct.
During this epoch, unambiguous placental mammals make their way into India in spite of its isolation, probably by rafting like the many placental groups in Madagascar, or perhaps brief connections with Africa and Europe (the latter still an archipelago). [[Hyaenodonts]] are an endemic african clade, first showing outside of the continent in the Paleocene of India and Europe,<ref>Floréal Solé & Thierry Smith, Dispersals of placental carnivorous mammals (Carnivoramorpha, Oxyaenodonta & Hyaenodontida) near the Paleocene-Eocene boundary: a climatic and almost worldwide story, GEOLOGICA BELGICA (2013) 16/4: 254-261</ref>. [[Glires]] evolved in Asia, but a lineage became isolated in India, where it gave rise to the lagomorphs.<ref>Rose K.D., Deleon V.B., Mmissian P., Rana R.S., Sahni A., Singh L. & Smith T. (2008). – Early Eocene lagomorph (Mammalia) from western India and the early diversification of Lagomorpha. – Proc. Royal Society B, RSPB 2007.1661.R1</ref>
For a while it was theorised that [[ostriches]] evolved in India during this epoch, under the assumption that european ratites like ''[[Palaeotis]]'' represented recent asiatic migrations. However, the first unambiguous ostriches are now thought to have evolved in Africa, with [[Eogruiidae|eogruiids]] having occupied their ecological niche in Asia; likewise, european ratites are now thought to be among the oldest known,<ref>Buffetaut, E.; Angst, D. (November 2014). "Stratigraphic distribution of large flightless birds in the Palaeogene of Europe and its palaeobiological and palaeogeographical implications". Earth-Science Reviews. 138: 394–408. doi:10.1016/j.earscirev.2014.07.001.</ref> and probably evolved independently there, being unrelated to ostriches. Still, India probably had a thriving [[paleognath]] fauna; the volant ancestors of [[kiwis]] and [[elephant birds]] presumably flew from there to Oceania and Madagascar respectively,<ref>Mitchell, K. J.; Llamas, B.; Soubrier, J.; Rawlence, N. J.; Worthy, T. H.; Wood, J.; Lee, M. S. Y.; Cooper, A. (2014-05-23). "Ancient DNA reveals elephant birds and kiwi are sister taxa and clarifies ratite bird evolution". Science. 344 (6186): 898–900. doi:10.1126/science.1251981. PMID 24855267.</ref> while the mysterious ''[[Hypselornis]]'' may represent an indigenous clade.
[[Caecillians]] are an indigenous gondwannan clade, but their absence in Madagascar suggests that the asian species have descended from african species that colonized India as it drifted north.<ref>Phylogenetic relationships of Indian caecilians (Amphibia:
Gymnophiona) inferred from mitochondrial rRNA gene sequences, Department of Zoology, The Natural History Museum, London SW7 5BD, UK b Institute of Biomedical and Life Sciences, Division of Molecular Genetics, University of Glasgow, Pontecorvo Building, 56 Dumbarton Rd,
Glasgow G11 6NU, Scotland, UK c Department of Zoology, University of Kerala, Kariavattom 695 581, Thiruvananthapuram, Kerala, India
Received 27 June 2001; received in revised form 17 December 2001</ref>
==Eocene Fauna==
By this time India already has an extensive placental fauna (as well as [[metatherians]] like ''[[Indodelphis]]''), but in its isolation there are still high degrees of endemism, with some clades like [[anthracobunids]] not being found elsewhere. The most notorious endemic mammals are [[cetaceans]], which are in fact restricted to the Indian Subcontinent until the evolution of the marine "[[protocetids]]". Eocene India is also rich in [[bat]] remains, including many representatives of modern groups, though its unclear if this indian chiropteran fauna represents an adaptive radiation or simply that bat fossils elsewhere are rare.<ref>Eiting, T.P.; Gunnell, G.F. (2009). "Global completeness of the bat fossil record". Journal of Mammalian Evolution. 16: 151–173. doi:10.1007/s10914-009-9118-x.</ref>
During this time [[ranids]], [[lagomorphs]] and [[hyaenodonts]] disperse out of India, establishing their cosmopolitan ranges.
==References==
[[Category:Historical continents]]
June 11, 2018 at 02:32AM
