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Temporal range: Campanian, 73 Ma
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Sauropterygia
Order: Plesiosauria
Family: Elasmosauridae
Genus: Nakonanectes
Serratos et al., 2017
Type species
Nakonanectes bradti
Serratos et al., 2017

Nakonanectes bradti is an elasmosaurid plesiosaur of the late Cretaceous found in 2010 the state of Montana in the United States. It is one of the earliest known elasmosaurids to have lived in North America. Unlike other elasmosaurids, it has a relatively short neck.


In November 2010, hunter David Bradt stumbled on an elasmosaur fossil in a canyon on the Charles M. Russell National Wildlife Refuge. The specimen proved to be a new, short-necked species of elasmosaur, subsequently named Nakonanectes bradti.[1][2]

The type specimen, MOR 3072, was nearly complete. This included the skull, a part not often found intact in Elasmosauridae fossils. Other elements of the fossil included the anterior cervical vertebrae, partial dorsal and caudal vetebrae, incomplete fore and hind limbs, gastralia, partial pectoral and pelvic girdles, and ribs.[2]

The fossil was found in the Bearpaw Formation, a late Campanian/early Maastrichtian rock, making it one of the earliest known elasmosaurids to have lived in the Western Interior Seaway.[2]

N. bradti was only 5.1 to 5.6 metres (17 to 18 ft) in length, making it one of the smallest elasmosaurids known.[2] It also had a much shorter neck that most eleasmosaurids, with only 39 to 42 cervical vertebrae.[2]


Danielle Serratos, Patrick Druckenmiller, and Roger Benson found that N. bradti is similar to the Aristonectinae, short-necked elasmosaurids known from fossils collected in South America. This indicates that short-necked elasmosaurids evolved in multiple locations on the globe.[2]


  1. ^ "New prehistoric sea creature discovered after Montana hunter finds exposed fossils". Associated Press. April 14, 2017. Retrieved November 8, 2017.
  2. ^ a b c d e f Serratos, Danielle J.; Druckenmiller, Patrick; Benson, Roger B.J. (2017). "A new elasmosaurid (Sauropterygia, Plesiosauria) from the Bearpaw Shale (Late Cretaceous, Maastrichtian) of Montana demonstrates multiple evolutionary reductions of neck length within Elasmosauridae". Journal of Vertebrate Paleontology: e1278608. doi:10.1080/02724634.2017.1278608.