Olssonia, Sanders & Merle & Puillandre, 2019

Sanders, Malcolm T., Merle, Didier & Puillandre, Nicolas, 2019, A review of fossil Bursidae and their use for phylogeny calibration, Geodiversitas 41 (5), pp. 247-265 : 254

Genus Olssonia n. gen.

urn:lsid:zoobank.org:act:9BB6F0C9-71ED-4F96-BAE8-3BA325B57714

TYPE SPECIES. — Bursa chira Olsson, 1930 .

DERIVATIO NOMINIS. — Dedicated to the American palaeontologist A. A. Olsson.

SPECIES INCLUDED. — Olssonia chira ( Olsson, 1930) n. comb., O. yasila ( Olsson, 1930) n. comb.

DISTRIBUTION. — Olssonia n. gen. is a genus restricted to the Eocene to early Miocene of Peru.

DIAGNOSIS. — Shell biconic, dorsoventrally compressed, shortspired, with 7 primary cords on the convex part of the whorl, all but P1 evenly reduced in variceal and intervariceal intervals of each whorl (P1 hardly more expressed than other cords); posterior siphonal canal short; varices strictly aligned; prominent columellar callus.

COMPARISONS. — Olssonia n. gen. resembles Marsupina but possesses a lesser number of primary cords on the convex part of the whorl (7 in Olssonia n. gen., 8 in Marsupina ). It resembles Aspa but has a much more prominent columellar callus, it is much more granulose, and it has a more sharply defined shoulder and a wider spire angle. Olssonia n. gen. resemble Bufonaria ( Fig. 3B ), with the same straight anterior siphonal canal, but lacks a spine or blade on the posterior siphonal canal ( Fig. 3B ; white arrow).

REMARKS

The representatives of this genus are the oldest confirmed Bursidae ; as such they can be used to calibrate the node Bursidae .

Figures

FIG. 3. — Recent Bursidae: A, IM-2008-5350, Bursa condita (Gmelin,1791), « Nouvelle Calédonie », Jousseaume coll.; B, IM-2007-43072, Bufonaria perelegans Beu,1987,Santo Marine Biodiversity Survey 2006,Vanuatu;C, IM-2009-11906,Bursa corrugata (Perry,1811),Dakar’09,Senegal;D, IM-2007-43063,Tutufa rubeta (Linnaeus, 1758), Santo Marine Biodiversity Survey 2006, Vanuatu; E, IM-2007-40338, Bursa latitudo Garrard, 1961, Exploration de la Biodiversité et Isolement en mer du Corail,Nouvelle Calédonie;F, IM-2009-5150, Lampadopsis rhodostoma (G.B. Sowerby II, 1835), MAINBAZA,Mozambique channel; G, IM-2009-5148, Bursa granularis (Röding, 1798), juvenile, MAINBAZA, Mozambique channel; H, IM-2009-11653, Bursa quirihorai Beu, 1987, Exploration de la Biodiversité et Isolement en mer du Corail, New Caledonia. All are ventral views. Scale bars: A-D, 2 cm; E-H, 1 cm.