Benenitra (Sakamena Fm.) (Permian of Madagascar)

Also known as Morondava Basin

Where: Tulear, Madagascar (23.5° S, 45.1° E: paleocoordinates 52.9° S, 26.5° E)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Lower Sakamena Formation (Sakamena Group), Lopingian (259.9 - 252.2 Ma)

• "Locally, the top of the Permian has been recognized by a prominent nodular layer, above which the nature of the sedimentary record is indicative of the Middle Sacamena Formation, dated throughout the island as Lower Triassic. According to Germain, the aquatic reptiles come from just below this horizon. The spore and pollen flora confirms the Upper Permian age for the beds containing the fossil reptiles." (Carroll, 1981 p. 338)

• member-level stratigraphic resolution

Environment/lithology: paralic; coarse-grained, micaceous, quartzose sandstone

• "The environment of the Madagascar localities unfortunately cannot be unequivocally established. [...] one can imagine a mixed environment that would have had a continuous transition from freshwater streams and lakes to brackish and shallow-water marine, seemingly ideal conditions for the evolution of marine reptiles." (Carroll, 1981 p. 338)

•"There is no evidence of the environment having been anaerobic [...] " (ibidem, p. 339)

• "The matrix is a course, dirty arkose, with large pieces of orthoclase as well as quartz, flakes of graphite and mica. The presence of feldspars, graphite and mica indicates relatively rapid burial of the sediments, without intense surface weathering. There are also many clay pebbles, suggestive of reworking partially indurated sediments. Such sediments may be derived from the weathering

•of granites such as the crystalline massif that makes up the core of the island. Garnet, zircon, tourmaline and one collophane grain were observed."

Size class: macrofossils

Collected by J. Colcanap, J. Piveteau in 1909, 1925

Primary reference: R. L. Carroll. 1981. Plesiosaur Ancestors from the Upper Permian of Madagascar. Philosophical Transactions of the Royal Society of London B 293(1066):315-383 [J. Mueller/T. Liebrecht/T. Liebrecht]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 85506: authorized by Johannes Mueller, entered by Torsten Liebrecht on 05.01.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

Osteichthyes
 Dicynodontia -
Dicynodontia indet. Owen 1859 dicynodont
"a very much worn tooth"
 Synapsida -
Theriodontia indet. Owen 1876 therapsid
"symphysial region [...] broken on all bone surfaces"
Reptilia
 Eosuchia - Claudiosauridae
Claudiosaurus germaini Carroll 1981 diapsid
MNHN (PM) 1909-3-13, 1909-3-25, 1909-3-37, 1909-3-43, 1925-5-85, 1925-5-90, 1925-5-102, 1925-5-111, 1925-5-120; includes elements that were formerly identified as Tangasaurus