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Biscarri, Isona (Cretaceous of Spain)

Where: Cataluña, Spain (42.1° N, 1.1° E: paleocoordinates 34.1° N, 0.9° E)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: La Posa Formation (Tremp Group), Late/Upper Maastrichtian (70.6 - 66.0 Ma)

• La Posa Grey Marls = "lower Member" of Tremp Formation. Layer with eggs is at the top of an 80 m thick succession of gray marls, shales, lignites, and limestones within this member.

• bed-level stratigraphic resolution

Environment/lithology: lagoonal or restricted shallow subtidal; lithified, burrowed, bioturbated, pyritic, gray marl

• "the profile was within the phreatic nape, below the vadose zone. These features indicate water-saturated sediments in a reducing coastal environment, from peritidal swamp (lignites and limestones) to tidal flats (grey marls)...water-logged tidal flat sediments from a perilagoonal environment...the nest was flooded and covered with mud and subsequently perforated by the growth of plant roots associated to the prograding salt-marsh."
• "a homogeneous, grey-coloured marl with iron-encrusted root casts (rhizoliths)...the eggs contain the same types of grey marl that underlie them, and contain framboidal pyrite encrusting the interior side of the eggshells. The marls bear iron-reduced colours and locally contain bioturbation structures (burrows) preserved as siderite concretions that are diagenetic products of the first-formed hydroxides. Leaching features, nodulization or mottling (marmorization) are absent."

Size classes: macrofossils, mesofossils

Preservation: trace

Collection methods: surface (in situ),

Primary reference: J. J. Moratalla. 1998. Spanish dinosaur eggs. In A. M. G. de Carvalho, A. M. Andrade, V. F. dos Santos, J. Cascalho, R. Taborda, (eds.), I Encontro Internacional sobre Paleobiologia dos Dinossáurios. Museu Nacional de História Natural, Lisboa 26-35 [M. Carrano/M. Carrano] more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 13331: authorized by Matthew Carrano, entered by Matthew Carrano on 26.02.2002

Creative Commons license: CC BY (attribution)