This study presents six new species of Asterina (Asterinaceae), A. indodeightonii, A. mioconsobrina, A. miosphaerelloides, A. neocombreticola, A. neoelaeocarpi and A. presaracae, on fossil angiosperm leaf remains recovered from the Siwalik sediments (mid-Miocene to early Pleistocene) of Arunachal Pradesh, eastern Himalaya. On the basis of leaf architecture, host leaves resemble the modern genera Actinodaphne (Lauraceae), Anthocephalus (Rubiaceae), Combretum (Combretaceae), Lindera (Lauraceae), Unona (Annonaceae) and one unidentified dicotyledonous plant. The in situ occurrence of Asterinaceae on these angiosperm leaf remains suggests diverse fungal associations in the phylloplane of ancient evergreen-deciduous tropical forest of Siwalik. The diversity of Asterinaceae also supports the rise of plant pathogenic forms during the mid-Miocene to early Pleistocene for which host plant diversity and environment may have played significant roles. Similar host parasitic interactions in modern Asterina spp. further support a co-evolutionary trend since the Neogene in Asterinaceae. © 2017 The Linnean Society of London.

SUBIR BERA

Botany

MANDAL) A V (NEE

M A KHAN

M BERA

D L DILCHER

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Botanical Journal of the Linnean Society

Here, we report fossil leaves, woods, and pollen grains comparable to Calophyllum L. (mainly to Calophyllum inophyllum L. and Calophyllum polyanthum Wall. ex Choisy) of Calophyllaceae from the upper (Kimin Formation, late Pliocene-early Pleistocene), middle (Subansiri Formation, Pliocene) Siwalik sediments of the Arunachal sub-Himalaya, and lower (Gish Clay Formation of Sevok Group; middle to late Miocene) Siwalik sediments of the Darjeeling foothills, eastern Himalaya. Their presence indicates a warm and humid tropical environment in the region during the period of Siwalik sedimentation. Considering all records of Calophyllum, it is suggested that Calophyllum was a frequent forest element throughout the period of Siwalik sedimentation during the Neogene (Miocene time). At present, C. polyanthum grows in the eastern Himalaya, but C. inophyllum is totally absent from north-eastern regions suggesting differential adaptability of these taxa to changing ecoclimatic conditions. Distinct climate change in the area, possibly related to the Himalayan Orogeny during Miocene–Pleistocene times, might have caused the disappearance of C. inophyllum from the entire eastern Himalaya and north-east Indian plains and a move to littoral/coastal and swampy forests of India and other adjoining south-east Asian regions, Polynesia, and the east coast of Africa. The past global distribution of Calophyllum is also discussed, and it is suggested that India may have been its primary centre of origin. This is the first time Cenozoic fossil leaves Calophyllum siwalikum Khan, R.A.Spicer & Bera, sp. nov. comparable to C. inophyllum are described using the both macro- and micromorphological characters. © 2017, Springer-Verlag Wien.

Plant Systematics and Evolution

Evidence for diversification of Calophyllum L. (Calophyllaceae) in the Neogene Siwalik forests of eastern Himalaya

Mastixioids in the family Cornaceae, are presently native only in limited areas of Asia, they have rich fossil fruit record in Cenozoic sediments of Europe and North America, but unfortunately none have been reported from Cenozoic sediments of India and Asia until now. Here, we report the occurrence of leaf remains (both impression and compression) along with carbonised fruits, resembling morphologically and anatomically those of the extant endemic species Mastixia arborea C.B. Clarke. Our materials were recovered from the middle Miocene to early Pleistocene Siwalik sediments exposed around West Kameng and Papumpare districts in Arunachal Pradesh, eastern Himalaya. These new fossil materials confirm the existence of Mastixia in the Miocene-Pleistocene Siwalik forests in India. At present the modern analogue does not grow in the eastern Himalaya and is endemic to the tropical evergreen forests of the Western Ghats, situated at the same palaeolatitude as the fossil locality. Extinction from the entire eastern Himalaya and probable movement of this taxon to the Western Ghats is likely due to climate change in the area, related to the Himalayan Orogeny during Miocene–Pleistocene times. The disappearance of Mastixia from this area may be related to the gradual intensification of rainfall seasonality since the late Miocene. The recovery of this species and our earlier-described evergreen taxa from the same Siwalik time (Mio-Pleistocene), suggest the existence of tropical, warm and humid climatic conditions during the period of deposition. The leaf and fruit remains are here described as new species, namely Mastixia asiatica Khan, Bera M et Bera S, sp. nov. and Mastixia siwalika Khan, Bera M et Bera S, sp. nov. respectively. This report documents the first fossil record of Mastixia leaf remains using both macro and micromorphological characters. We also review the historical phytogeography, and highlight the phytogeographic implication of, the mastixioids. © 2017 Elsevier B.V.

Fulltext

Review of Palaeobotany and Palynology

First occurrence of mastixioid (Cornaceae) fossil in India and its biogeographic implications

We report the occurrence of two leaf impressions and one leaf compression along with one winged fruit and two fruiting calyx lobes, resembling those of Shorea Roxburgh ex C. F. Gaertner, in the lower Siwalik (Dafla Formation, middle to upper Miocene), middle Siwalik (Subansiri Formation, Pliocene) and upper Siwalik (Kimin Formation, upper Pliocene to lower Pleistocene) sediments exposed in Arunachal Pradesh, eastern Himalaya. We determine their taxonomic positions based on morphological comparison with similar extant and fossil specimens and discuss their phytogeographic and paleoclimatic implications in terms of the distribution and habitat of fossil and modern populations. The Miocene winged fruit is recognized as Shorea pinjoliensis Khan, R.A. Spicer et Bera, sp. nov. while the Pliocene and Plio-Pleistocene fruiting calyx lobes are recognized as Shorea bhalukpongensis Khan, R.A. Spicer et Bera, sp. nov. and Shorea chandernagarensis Khan, R.A. Spicer et Bera, sp. nov. respectively. Based on leaf architecture the Miocene, Pliocene and Plio-Pleistocene leaves are recognized as Shorea mioobtusa Khan, R.A. Spicer et Bera, sp. nov., Shorea pliotumbuggaia Khan, R.A. Spicer et Bera, sp. nov. and Shorea nepalensis Konomatsu et Awasthi respectively. The discovery of members of Shorea indicates that they had arrived in a tropical, warm and humid eastern Himalaya by the Mio-Pleistocene. Present and earlier records of Shorea suggest that this genus was a common forest element during Neogene (Miocene time) as well as in the Siwalik forests including Arunachal sub-Himalaya. In this paper, we also review in detail the biogeographic history and suggest possible migration routes of the genus. © 2016 Elsevier B.V.

Occurrence of Shorea Roxburgh ex C. F. Gaertner (Dipterocarpaceae) in the Neogene Siwalik forests of eastern Himalaya and its biogeography during the Cenozoic of Southeast Asia

Seven fossil leaves with cuticle described here were collected from the lower, middle and upper strata of Siwalik (middle Miocene-lower Pleistocene) sediments of Arunachal Pradesh, India. A detailed comparison of the cuticular analysis of the fossils and their living relatives indicate that these fossil species belong to Dysoxylum raptiensis, Macaranga cf. denticulata, Calophyllum suraikholensis, Combretum prechinense, Actinodaphne palaeoangustifolia, Shorea siwalika and Dipterocarpus koilabasensis. Among these fossil species C. prechinense has been described as a new species. The present day distribution of the modern equivalent taxa of the fossils, structural features and the micro-morphological features of the fossil leaves together with epiphyllous fungal remains collectively indicate the prevalence of a warm humid tropical climate in this area during Siwalik sedimentation. The cuticular micro-morphological features help to confirm the identification of their leaf compressions to the species level and are clearly indicative of mesophytic ecological conditions that reflect a tropical climate with high precipitation. This is the first time Cenozoic fossil leaves of Dysoxylum, Macaranga, Calophyllum, Combretum, Actinodaphne, Shorea and Dipterocarpus are described using the micromorphology of their epidermis. © 2014 Elsevier B.V.

Leaf cuticular morphology of some angiosperm taxa from the Siwalik sediments (middle Miocene to lower Pleistocene) of Arunachal Pradesh, eastern Himalaya: Systematic and palaeoclimatic implications

Four legume fruits (Fabaceae) from the Siwalik sediments (middle Miocene to lower Pleistocene) of Darjeeling and Arunachal Pradesh of Eastern Himalaya are described here. One fossil fruit, Dalbergia prelatifolia sp. nov., is recovered from the lower part of the Siwalik succession (Gish Clay Formation of Sevok Group; middle to upper Miocene) of Darjeeling foothills. Mastertia neoassamica sp. nov. and Acacia miocatechuoides sp. nov. are collected from the lower part of the Siwalik succession (Dafla Formation; middle Miocene to upper Miocene), while Pongamia kathgodamensis Prasad is recovered from the upper part of the Siwalik succession (Kimin Formation; upper Pliocenelower Pleistocene) of Arunachal sub Himalaya. Their presence indicates a warm and humid tropical environment in the region during the Siwalik sedimentation. © 2014 Geological Society of India.

Journal	Data powered by TypesetBotanical Journal of the Linnean Society
Publisher	Data powered by TypesetOxford University Press
ISSN	0024-4074
Open Access	No