nannotax and discoasters

12
Nannotax and Discoasters Jeremy R. Young, University College London

Upload: sylvia-bishop

Post on 17-Jan-2018

225 views

Category:

Documents


0 download

DESCRIPTION

Nannotax 3 – launched sept 2013 Continuously developed since e.g. added full coverage of extant nannos, Neptune database linkage, comprehensive rewriting of the code Now about 17,000 images 2,700 taxa many users (ca 1500 sessions per week, average session length 13 mins) post INA 15 Farinacci Catalog has 4100 taxa (inc. 214 discoasters)

TRANSCRIPT

Page 1: Nannotax and Discoasters

Nannotax and Discoasters

Jeremy R. Young,University College London

Page 2: Nannotax and Discoasters

Nannotax 3 – launched sept 2013Continuously developed since- e.g. added full coverage of extant nannos, Neptune

database linkage, comprehensive rewriting of the code- Now about 17,000 images- 2,700 taxa- many users (ca 1500 sessions per week, average session

length 13 mins)- post INA 15 Farinacci Catalog has 4100 taxa (inc. 214

discoasters)

Page 3: Nannotax and Discoasters

The main part of this talk was given using a live link to the Nannotax website not powerpoint slides.

Specifically it consisted of an overview of species level taxonomy of discoasters as presented on nannotax - with primary emphasis on the Neogene. The next

The other slides were briefly discussed

Page 4: Nannotax and Discoasters

Neogene discoaster groups on Nannotax - as discussed using the website

Page 5: Nannotax and Discoasters

Paleogene discoaster groups (modified from Romein 1979, Theodoridis 1984, Bown 2005 etc.), as discussed using the website.NB The D. araneus group was separated out following comments made during the workshop

Page 6: Nannotax and Discoasters

Pliocene Discoaster cyclicity

Through the Late Pliocene there is strong climatic cyclicity, dominated by obliquity.This is strongly reflected in Discoaster abundancesSuccession of studies by Backman and Chepstow-Lusty

Chepstow-Lusty, A., Shackleton, N. J. & Backman, J. 1992. Upper Pliocene Discoaster abundance variations from the Atlantic, Pacific and Indian Oceans: the significance of productivity pressure at low latitudes. Memorie di Scienze Geologiche 43, 357-373.

Page 7: Nannotax and Discoasters

Site 504

key documentation of synchrony in an event using cyclostratigraphy

Discoaster brouweri extinction

Page 8: Nannotax and Discoasters

Neogene discoasters overview (from Young 1998)

Is this a valid overview? How can it be improved?

Page 9: Nannotax and Discoasters

terminology (from Young et al. 1997) http://ina.tmsoc.org/terminology/discoasters.htm

Page 10: Nannotax and Discoasters

trends • reduced rays• reduced calcification• increased proximal-distal differentiation

Page 11: Nannotax and Discoasters

Lambert 2005Cahiers de Micropaleontologie

Kutei BasinIndonesia

an alternative approach to nannofossil taxonomy

how can we describe the cloud of morphotypes within particularly 6-rayed bifurcate discoasters ?

Page 12: Nannotax and Discoasters