Marambionectes

Marambionectes
Temporal range: Late Cretaceous (Upper Maastrichtian)
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Restoration
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: †Sauropterygia
Order: †Plesiosauria
Family: †Elasmosauridae
Clade: †Weddellonectia
Genus: †Marambionectes
Species:
†M. molinai
Binomial name
†Marambionectes molinai
O'Gorman et al., 2024

Marambionectes (meaning "Marambio Island swimmer") is an extinct genus of weddellonectian elasmosaurid plesiosaur from the Late Cretaceous López de Bertodano Formation of Antarctica. The genus contains a single species, M. molinai, known from a partial skeleton.

Discovery and naming

The Marambionectes holotype specimen, IAA-Pv 752, was discovered in 2018 in sediments of the López de Bertodano Formation (unit 9) near on Marambio (Seymour) Island of James Ross Archipelago, Antarctica. The specimen is partially articulated and incomplete, consisting of the basioccipital, mandible, some teeth, cervical, pectoral, dorsal, and caudal vertebrae, ribs, an ilium, the right humerus and ulna, and a femur. The specimen belonged to an adult animal.[1]

In 2024, O'Gorman et al. described Marambionectes molinai as a new genus and species of elasmosaurid plesiosaur based on these fossil remains. The generic name, Marambionectes, combines a reference to Marambio Island, where the fossil material was found, with the Greek word "nectes", meaning "swimmer". The specific name, molinai, honors the Argentinian fossil preparator Omar J. Molina and his Antarctic field work.[1]

Classification

In their phylogenetic analyses, O'Gorman et al. (2024) recovered Marambionectes as a derived member of the elasmosaurid clade Weddellonectia, as the sister taxon to the Aristonectinae. Their results are shown in the cladogram below:[1]

Elasmosauridae

References

  1. ^ a b c O'Gorman, Jose P.; Canale, Juan I.; Bona, Paula; Tineo, David E.; Reguero, Marcelo; Cárdenas, Magalí (2024-12-31). "A new elasmosaurid (Plesiosauria: Sauropterygia) from the López de Bertodano Formation: new data on the evolution of the aristonectine morphology". Journal of Systematic Palaeontology. 22 (1). Bibcode:2024JSPal..2212302O. doi:10.1080/14772019.2024.2312302. ISSN 1477-2019.
  2. ^ O’Gorman, Jose P. (2020-03-13). "Elasmosaurid phylogeny and paleobiogeography, with a reappraisal of Aphrosaurus furlongi from the Maastrichtian of the Moreno Formation". Journal of Vertebrate Paleontology. 39 (5): e1692025. doi:10.1080/02724634.2019.1692025. ISSN 0272-4634. S2CID 215756238.