Autumn General Meeting 2010 – Report

The meeting was organised and hosted by Alan Lord and chaired by John Whittaker in the Arthur Holmes Room of the Geological Society of London, Burlington House, Piccadilly.

John Whittaker gave a short update on the latest TMS Special Publications available via the Geological Society Publishing House. Initial reviews of “Ostracods in British Stratigraphy” have praised its presentation and quality of its plates, thoroughly recommending its purchase. John also described the official launch of the “Curry Volume” in Chichester on October 2nd attended by Dennis’ family.

Giles Miller (Natural History Museum) started off proceedings by showing us a series of beautiful 3-D plastic models (c.15cm long) of Pattersoncypris micropapillosa Bate 1972, created from the 3-D computer scans taken at the ESRF synchrotron at Grenoble. Apparently the models are created using two lasers focussed in to a bath of liquid resin that hardens where the beams cross. Ray Bate, who is donating them to the NHM, kindly paid for the models. Other models of such scans now form a display at the NHM based on recent research published in Science suggesting that ostracods were reproducing using giant sperm as far back as the Cretaceous (see TMS Newsletter No. 80, p.19 and search for ostracod on

Ian Boomer (University of Birmingham) has just started work on some Miocene (probably Burdigallian) ostracods from sediments around Lake Victoria (Kenya). Samples were provided by Laura Basell (University of Southampton) as part of a palaeoarchaeological study sponsored by a NERC URGENCY grant. The sediments are full of vertebrate fossils (turtles, crocs, lizards, rhino and even the tusk of a proto-elephant). Large numbers of worked stones by early hominins are also common in the study area. The freshwater ostracods are dominated by Limnocythere with Illycypris, Heterocypris, Potamocypris and Darwinula but few if any Candonids. Preservation was variable from good to clearly recrystralised.

Dave Horne (Queen Mary, University of London) described the history behind finds of Terrestricythere in the UK, the genus first being described from the Far East. The genus lives in brackish waters but is able to crawl around in damp vegetation free of water. A new record of Terrestricythere from Tollesbury in Essex, was studied by Lauradana Day and Toyah Parker as part of their undergraduate degrees. Lauradana examined cores from Tollesbury to ascertain if there was a fossil record of the ostracod or whether it was a recent ‘invader’. To date, although common on the ?surface?, none has been seen from the core. However as agglutinating foraminifera, but no calcareous foraminifera, are present it suggests that decalcification may be an issue.

Ginny Benardout has just started her doctoral work at Queen Mary,  University of London (supervised by Dave Horne and Steve Brooks), initially looking at Hoxnian interglacial sediments (MIS11) at Beeches Pit, West Stow in Suffolk. Ginny is utilising the Mutual Ostracod Temperature Range (MOTR) methodology developed by Dave Horne, in conjunction with chironomid temperature data. Initial results suggest a mean temperature in winter (Jan) of -8oC (range -10 to -2oC) and in summer (June) of +20oC (range 16-22oC). Work will continue to refine the MOTR database/methodology.

Jonathan Holmes (UCL) discussed Holocene ostracods from a core provided by Matthew Jones (University of Nottingham) from Lake Pareshan in SW Iran. The ostracod assemblages are dominated by Cypideis torosa (lower succession) and Limnocythere inopinata (upper succession) with a switch over at c.2ky. Non-marine ostracods are sensitive to solute chemistry (rather than salinity per se) with C. torosa preferring a Na/Cl brine with an alkalinity/Ca ratio <1 and L. spinosa favouring a ?Na-CO3 brine with an alkalinity/Ca ratio >1. However, there is no know solute pathway to explain the switch in the middle of the core (also seen briefly in the lower part of the core; c.4ky) in terms of evaporation alone, suggesting a switch in water source and the hinterland geology it flowed from, though this requires further investigation.

Lee Bradley (University of Liverpool) described his doctoral work on Holocene deposits form the south-western Black Sea. Lee is working in conjunction with another doctoral student, Lorna Williams, who is at Memorial University, Newfoundland, each looking at different cores. Having already examined the dinocysts Lee has only recently started looking at the ostracods (pollen and geochemistry studies still to come). Lee has documented a switch from brackish to marine conditions at c.7.5ka using both dinocysts and ostracods. However, this switch, marking the reconnection of the Black and Mediterranean seas was gradual rather than sharp.

Steve Sweetman (University of Portsmouth) and Dave Horne described the sediments and ostracods, respectively, from the Wessex Formation (Barremian) on the Isle of White. Most of the formation is heavily influenced by Cretaceous pedogenesis with few fossils evident. The ostracods were only found in a small number of “plant debris beds” (6 out of the 27 that had vertebrate finds). These are thought to form as flood debris beds following post lightening induced wild fires and subsequent heavy rains. The ostracod fauna is dominated by Cypridea (4 spp) and the oldest known member of the Notodromadinae. A short video of modern Notodromas monacha illustrated their unique lifestyle attached upside down to the underside of the water surface on a distinctive ovate flattened area on their ventral surface, where they feed on the hyponeuston.

Adrian Wood (University of Coventry) continued his discourse on the temporal biogeographical distribution of North Atlantic and Arctic cold-water shallow marine ostracod species from previous meetings. Adrian described the fauna from early Pliocene (OIS Si4 and/or Si6; c.4.6-4.9Ma) sediments from the West Netherlands Basin. The section studied was 125m think, marine at the base and showing freshwater (riverine?) influence at the top, though the talk concentrated on the basal marine succession. Using Mutual Climate Change indicators, assisted by having ten extant species, the basal marine section was shown to have experienced summer water temperatures of less that 10oC (today?s range is 5-15oC). However, winter temperatures were little different indicating either deep stable waters or stratification of the water column at that time. That the opening of the Bering Strait is dated as c.4.91Ma indicates migration of cold water ostracods into the Southern North Sea was rapid.

With sixteen people and eight talks this was the largest attendance of an TMS Ostracod Group meeting for many years. It was encouraging to meet several ‘new blood’ young ostracodologists just starting off on their respective doctoral studies. With the doom and gloom surrounding the micropalaeontology staff at the NHM this was indeed welcome news.

All in all this was an excellent meeting, as much for the gathering of friends as for the quality of the individual presentations. Thanks go to Alan Lord for organising the room and abstracts pamphlet.

Report compiled by Matt Wakefield (BG Group)