Head, Martin J. (2000): Geonettia waltonensis, a new goniodomacean dinoflagellate from the Pliocene of the North Atlantic region, and its evolutionary implications. Paleontological Society, Lawrence, KS, United States, Journal of Paleontology, 74 (5), 812-827, georefid:2001-052591

A new species of the unusual dinoflagellate cyst genus Geonettia de Verteuil and Norris, 1996a is here described from the Pliocene of the western North Atlantic and eastern England. Geonettia waltonensis new species is only the second species to be formally described for this genus, whose type, G. clineae de Verteuil and Norris, 1996a, has a range of Miocene through Pliocene. Geonettia is a gonyaulacalean, goniodomacean genus of the subfamily Pyrodinioideae and is closely related to Eocladopyxis Morgenroth, 1966 and Capisocysta Warny and Wrenn, 1997, also found in the Cenozoic. However, Geonettia is the only known dinoflagellate cyst genus to have plates that dissociate extensively on both epi- and hypocyst during excystment. Geonettia waltonensis has this style of excystment, but its hypocystal tabulation is more akin to Capisocysta lata Head, 1998a than to G. clineae. Comparison of tabulation and other morphological features suggests that during the late Miocene, Capisocysta lata evolved from Geonettia waltonensis or a closely related species through failure of its epicystal plates to dissociate. Geonettia waltonensis probably did not evolve directly from G. clineae but may represent a separate lineage within Geonettia that arose during the Miocene.
West: -70.0143 East: 1.4500 North: 70.2730 South: 35.2939
West: NaN East: NaN North: NaN South: NaN
West: NaN East: NaN North: NaN South: NaN
Expedition: 105
Site: 105-645
Expedition: 93
Site: 93-603
Expedition: 95
Site: 95-603
Data access:
Provider: SEDIS Publication Catalogue
Data set link: http://sedis.iodp.org/pub-catalogue/index.php?id=2001-052591 (c.f. for more detailed metadata)
This metadata in ISO19139 XML format