''Plesiopharos'' (derived from the Greek words πλησίος (plesios), "close" and φάρος (pharos), " lighthouse", because its

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

was found in the vicinity of a lighthouse +

rom São Pedro de Rom, or ROM may refer to: Biomechanics and medicine * Risk of mortality, a medical classification to estimate the likelihood of death for a patient * Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac * ...

Moel) is an extinct plesiosaur that lived in what is now

Portugal Portugal, officially the Portuguese Republic, In recognized minority languages of Portugal: :* mwl, República Pertuesa is a country located on the Iberian Peninsula, in Southwestern Europe, and whose territory also includes the Macaronesian ...

, in the Early Jurassic. Specifically, it was discovered in São Pedro de Moel, Marinha Grande, from which the type species' binomial name, ''Plesiopharos moelensis'', derives from. At the time of its publication (2021), this plesiosaur was the most complete and oldest known from the

Iberian Peninsula The Iberian Peninsula (), ** * Aragonese and Occitan: ''Peninsula Iberica'' ** ** * french: Péninsule Ibérique * mwl, Península Eibérica * eu, Iberiar penintsula also known as Iberia, is a peninsula in southwestern Europe, defi ...

Discovery

The fossils were found by two collectors, António Silva (1999) and Vítor Teixeira (2012) and who donated them to the Lourinhã Museum in 2017 and were completely prepared in the Dino Parque laboratory.

Description

The ''Plesiopharos'' holotype (ML 2302) consists of parts of the fin of the arm (humerus and radius), of the right leg (femur), pelvic girdle (pubis, ilium and ischium) of the thorax (vertebrae, ribs and gastralia) and of the neck (cervical vertebra). It would be an adult animal with an estimated size between 2.5 and 2.8 m.

Classification

''Plesiopharos moelensis'' is classified as a basal member of

Plesiosauroidea Plesiosauroidea (; Greek: 'near, close to' and 'lizard') is an extinct clade of carnivorous marine reptiles. They have the snake-like longest neck to body ratio of any reptile. Plesiosauroids are known from the Jurassic and Cretaceous per ...

Stratigraphy

''Plesiopharos moelensis'' was discovered at Praia da Concha, São Pedro de Moel, Marinha Grande, in layers that belong to the

Coimbra Formation Coimbra (, also , , or ) is a city and a municipality in Portugal. The population of the municipality at the 2011 census was 143,397, in an area of . The fourth-largest urban area in Portugal after Lisbon, Porto, and Braga, it is the largest cit ...

, which date to the

Sinemurian In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.3 ± 2 Ma and 190.8 ± 1.5 Ma (million years ago). The Sinemurian is preceded by the Hettangian an ...

.Duarte, L.V., Comas-Rengifo, M.J., Silva, R.L., Paredes, R., and Goy, A. 2014. Carbon isotope stratigraphy and ammonite biochronostratigraphy across the Sinemurian–Pliensbachian boundary in the western Iberian margin. Bulletin of Geosciences 89: 719–736.

References

{{Taxonbar, from=Q107207764 Plesiosauroids Sauropterygian genera Sinemurian life Early Jurassic plesiosaurs of Europe Jurassic Portugal Fossils of Portugal Fossil taxa described in 2021