Penina eastern locality (Triassic to of Portugal)

Where: Algarve, Portugal (37.3° N, 8.1° W: paleocoordinates 17.1° N, 0.1° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Grès de Silves Formation, Carnian to Carnian (237.0 - 208.5 Ma)

• "The Penina Bonebed is located in the part of the Gres de Silves Formation termed ‘AB2’ (Fig. 1) and previously considered to be Rhaetian–Hettangian (latest Triassic–earliest Jurassic) in age. The bonebed is most likely older than Jurassic, however, because it is located considerably below Central Atlantic Magmatic Province (CAMP) basalts in local section. The Portuguese CAMP basalts have been radioisotopically dated at 198.1 Ma, which would place the basalts in the earliest Jurassic (Sinemurian). However, these dates need to be corrected for decay constant bias and are likely to be a few million years older. In any event, the Portuguese basalts are likely somewhat younger than many other radioisotopically dated CAMP sections in North America and North Africa. A more precise Triassic age determination of the bonebed is not currently possible, because the stratigraphy and geochronology of the Gres de Silves Formation have only been studied in cursory detail. Our research group is currently revising the geology of the formation, and we recently tentatively proposed, based on vertebrate biostratigraphy, that at least part of the ‘AB2’ unit (i.e., that containing the Penina Bonebed) is likely to be late Carnian–Norian in age" (Brusatte et al. 2014)

• formation-level stratigraphic resolution

Environment/lithology: fluvial-deltaic; lithified, argillaceous sandstone

• "Phases of relative aridity are suggested by the sporadic occurrence of gypsum. The palaeoenvironment can be reconstructed as a broad coastal plain with several streams flowing into the sea, and sediment from the nearby, raised hinterland accumulated in fans on the shore (Palain 1976). Schröter (1981) interpreted the mudstones as deltaic sediments with the lenses of sandstone being fluviatile deposits, e.g., from anastomosing deltaic streams. Alternatively, he pointed out that the mudstones might represent tidal sediments, and the lenses of sandstones could be the fillings of estuarine channels. However, Schröter (1981) did not observe tidal sedimentary structures, such as herringbone cross-stratification or flaser bedding, which detracts from the second interpretation."
• "The bone-bearing layer is eroded into surface stones ("LesesteinDecke") that consist of clayey sandstone. The fossil bones were either enclosed in these stones or weathered free from the rock matrix...The fossiliferous layers at both localities consist of lenses of sandstone within an approximately 200 m thick sequence of red mudstones, the thickest member of the Grès de Silves Formation."

Size class: macrofossils

Collected by Thomas Schröter in 1979-1980

Collection methods: surface (float),

Primary reference: F. Witzmann and T. Gassner. 2008. Metoposaurid and mastodonsaurid stereospondyls from the Triassic-Jurassic boundary of Portugal. Alcheringa 32:37-51 [R. Butler/R. Butler]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 82903: authorized by Richard Butler, entered by Richard Butler on 04.08.2008

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Amphibia
 Temnospondyli -
Temnospondyli indet.
 Temnospondyli - Metoposauridae
Metoposauridae indet.
Metoposauridae indet. Watson 1919 tetrapod