Abstract Detail

Paleobotany

Wheeler, Elisabeth [1], Srivastava, Rashmi [2], Manchester, Steven [3], Baas, Pieter [4].

Revisiting the Deccan Intertrappean Woods.

Since the 1920s numerous petrified woods have been reported from the Deccan Intertrappean Beds of India. Most were described and named during the 1950s to 1980s. At that time, it was thought the Deccan Traps were younger (Eocene) and so, not surprisingly, the woods were identified by their general similarity with present-day Indian woods. Now it’s known that the Deccan Intertrappean Beds are older (ca. 67-64 Ma, i.e., late Maastrichtian - early Danian). We examined thin sections, most of holotypes, of 43 species of Deccan woods and have been reassessing their affinities by more broadly comparing them anatomically with extant woods worldwide. At least 4 have features generally agreeing with the assigned generic name (Ailanthoxylon - Simaroubaceae, Garcinioxylon - Clusiacae, Leeoxylon - Vitaceae, Oleoxylon - Oleaceae) and represent the oldest known occurrence of woods with features of those genera. Others have combinations of features consistent with belonging to the family they were originally assigned, but the features are not unique to the genus implied by the name, e.g., Polyalthioxylon (Annonaceae), Barringtonioxylon (Lecythidaceae), Grewioxylon, Sterculioxylon (Malvaceae), Artocarpoxylon (Moraceae), Callistemonoxylon (Myrtaceae). Some have features of more than one family with the families belonging to the same order as the original assignment, e.g. Bischofinium, Bridelioxylon (Malpighiales); Burseroxylon, Heyneoxylon (Sapindales). Others we could not verify the suggested affinities or suggest reasonable alternatives, either because of poor preservation or the sample has a combination of features found in other families and orders. The woods we examined came from multiple localities. Taken as a group, the range of specific gravities of the Deccan woods appears comparable to present-day woods, ranging from very low to high. India had a nearly equatorial position during the latest Cretaceous; almost all other Maastrichtian and Paleocene wood localities are at higher latitudes. Today there is latitudinal variation in incidence of perforation plate type and axial parenchyma abundance. The Deccan woods indicate that there was also latitudinal variation in late Cretaceous angiosperms. They differ from Maastrichtian woods of the rest of world by having higher incidences of simple perforation plates (97% vs. 45%) and obvious axial parenchyma (41% vs. 15%).

Related Links:
wood anatomy web site

1 - DEPT OF WOOD & PAPER SCIENCE, 710 Dixie Trail, Raleigh, NC, 27607, USA
2 - Birbal Sahni Institute of Palaeobotany, 53 University Road, Lucknow, 226 007, India
3 - Florida Museum of Natural History, Dickinson Hall;1659 Museum Rd, Gainesville, FL, 32611-7800, USA
4 - Naturalis Biodiversity Center, Herbarium Division, PO Box 9517, LEIDEN, 2300 RA, Netherlands

Keywords:
wood anatomy
secondary xylem
Late Cretaceous
Paleocene.

Presentation Type: Oral Paper
Session: 23, Paleozoic and Mesozoic Paleobotany
Location: 102/Savannah International Trade and Convention Center
Date: Tuesday, August 2nd, 2016
Time: 11:30 AM
Number: 23013
Abstract ID:79
Candidate for Awards:None