Rio Potimalal (Jurassic to of Argentina)

Where: Mendoza, Argentina (36.0° S, 70.0° W: paleocoordinates 33.2° S, 32.5° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: La Manga Formation (Lotena Group), Middle Oxfordian to Middle Oxfordian (161.2 - 155.7 Ma)

• "In the Potimalal section, the La Manga formation consists of 10–15 m of fossiliferous deep-water deposits. There are two units. The lower unit is 2.5 m thick with a sharp base lithologically composed of skeletal wackestones and olive-grey calcareous claystones, stratified in tabular beds of medium thickness and partly massive. The upper unit is 11 m thick, and the base has a sharp contact. The fossil content is characterized by bivalves and ammonites. Sponges were found in small bioherms of the lower unit of the La Manga formation".

Environment/lithology: reef, buildup or bioherm; shelly/skeletal, calcareous lime mudstone

• The lower unit is 2.5 m thick with a sharp base lithologically composed of skeletal wackestones and olive-grey calcareous claystones, stratified in tabular beds of medium thickness and partly massive. Sponge facies correspond to siliceous sponge framestones.

Size class: macrofossils

• 67 specimens collected, most were complete sponges and larger fragments.

Preservation: original silica, replaced with calcite

Collected by Beresi, M.S., Zavattieri A.M., Papu O.

Collection methods: chemical, acetic,

• "Loose disassociated spicules of large hexactines (pen- tactines) and rhabdoactines from three specimens have been obtained through processing with an acid solution".

Primary reference: M. S. Beresi. 2003. Oxfordian sponge association from the Neuquen basin, Mendoza, west central Argentina. Journal of South American Earth Sciences 16:105-112 [J. Alroy/J. Martinelli/J. Martinelli]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 135242: authorized by John Alroy, entered by Julieta Martinelli on 21.10.2012

Creative Commons license: CC BY (attribution)

Taxonomic list

• "Sponges are stored in the collection of the DepartamentodePaleontolog ́ıayGeolog ́ıadelIANIGLA- Cricyt, Mendoza (IANIGLA-PI 924-981)".
Hexactinellida
 Innaecoeliida - Craticulariidae
Laocoetis sp. Pomel 1872 glass sponge
Laocoetis paradoxa Münster 1833 glass sponge
Laocoetis procumbens Goldfuss 1826 glass sponge
"Laocoetis parallela" = Craticularia parallela Goldfuss 1826 glass sponge
 Hexactinosa - Aulocalycidae
Polygonatium sphaeroides Schrammen 1937 glass sponge
 Hexactinosa - Euretidae
Ordinatus sp. Laubenfels 1955 glass sponge
Linonema calyx Schrammen 1937 glass sponge
 Hexactinosa - Cribrospongiidae
Cribrospongia sp. d'Orbigny 1849 glass sponge
Cribrospongia reticulata Goldfuss 1826 glass sponge