''Traskasaura'' (meaning "Trask lizard") is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus of basal

elasmosaurid Elasmosauridae, often called elasmosaurs or elasmosaurids, is an extinct family of plesiosaurs that lived from the Hauterivian stage of the Early Cretaceous to the Maastrichtian stage of the Late Cretaceous period (c. 130 to 66 mya). The taxo ...

plesiosaurs from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

(

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya ( million years ago) and 83.6 ± 0.7 m ...

age) Haslam Formation of

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

, Canada. The genus contains a single species, ''Traskasaura sandrae'', known from three partial skeletons. It is the first elasmosaurid discovered in and named from British Columbia.

Discovery and naming

The ''Traskasaura'' fossil material was discovered in outcrops of the Haslam Formation ( Nanaimo Group) on

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian province of British Columbia. The island is in length, in width at its widest point, and in total area, while are of land. The island is the largest ...

of British Columbia, Canada. The first discovered specimen was found in November 1988 by Michael Trask and his daughter Heather on the bank of the

Puntledge River The Puntledge River is a small river on Vancouver Island, British Columbia, Canada. It joins the Tsolum River to form the Courtenay River, which enters the Strait of Georgia at the city of Courtenay. Name origin The name is derived from that of ...

near Courtenay. Supported by

grants Grant or Grants may refer to: People * Grant (given name), including a list of people and fictional characters * Grant (surname), including a list of people and fictional characters ** Ulysses S. Grant (1822–1885), the 18th president of the U ...

from the province of British Columbia, the specimen began to be excavated and studied by Trask with assistance from paleontologists Rolf Ludvigsen and

Elizabeth Nicholls Elizabeth (Betsy) Laura Nicholls (January 31, 1946 – October 18, 2004) was an American-Canadian paleontologist who specialized in Triassic marine reptiles. She was a paleontologist at the Royal Tyrrell Museum in Alberta, Canada. Early l ...

. More than 40 local volunteers also assisted in collecting the specimen in 1990 with the help of additional grants. After collection, the skeleton was accessioned as specimen CDM 002 in the Courtenay & District Museum, where it was prepared over the following years. This work revealed the nearly complete, albeit poorly-preserved, skeleton of a fully-grown plesiosaur, with an estimated body length around . The specimen was noted for representing the first elasmosaurid discovered in British Columbia. In a 2002 paper detailing the Nanaimo Group fossil marine reptiles, Elizabeth Nicholls and Dirk Meckert preliminarily described CDM 002. They identified it as belonging to an indeterminate elasmosaurid, possibly a previously unrecognized taxon. However, given the poor preservation of the specimen, they refrained from naming it. A second partial specimen, cataloged as CDM 161, was found in 2020 on the bank of the Trent River near Highway 19. It consists of a mostly articulated, well-preserved skeleton, likely belonging to a young juvenile individual. A third specimen, CDM 2006.8.1, represented by a single right

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

, was found during the construction of this highway. It is intermediate in ossification (an indication of maturity) and size between the two more complete specimens. In a 2018 public poll, 48% of responding British Columbian voters selected the then-unnamed "Courtenay elasmosaur" as their preferred "provincial fossil". In 2023, the taxon was officially recognized as the emblematic Provincial Fossil of British Columbia. Prior to receiving a

scientific name In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

, the animal was referred to as the "Courtenay elasmosaur", "Puntledge elasmosaur", or "Haslam elasmosaur". The novelty and unique anatomy of the animal was reported in a 2024

conference A conference is a meeting, often lasting a few days, which is organized on a particular subject, or to bring together people who have a common interest. Conferences can be used as a form of group decision-making, although discussion, not always d ...

abstract for the Society of Vertebrate Paleontology's annual meeting. In 2025, F. Robin O'Keefe and colleagues described ''Traskasaura sandrae'' as a new genus and species of plesiosaurs based on these fossil remains. They established CDM 002, the more complete and first discovered specimen, as the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

specimen, and CDM 161 as the

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype (biology), isotype ...

. CDM 2006.8.1, the isolated humerus, was also referred to this species. The discovery of CDM 161 several years after the initial description of CDM 002 allowed for improved anatomical interpretations and comparisons with other taxa. The generic name, ''Traskasaura'', honours Michael and Heather Trask, the discoverers of the holotype. This is combined with "''saura''", the feminine

conjugation Conjugation or conjugate may refer to: Linguistics *Grammatical conjugation, the modification of a verb from its basic form *Emotive conjugation or Russell's conjugation, the use of loaded language Mathematics *Complex conjugation, the change o ...

of the

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

'' σαῦρος'' (''saûros''), meaning "lizard". The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''sandrae'', honours O'Keefe's mother, Sandra Lee O'Keefe (

née The birth name is the name of the person given upon their birth. The term may be applied to the surname, the given name or to the entire name. Where births are required to be officially registered, the entire name entered onto a births registe ...

Markey).

Classification

The ''Traskasaura'' specimens demonstrate a mosaic of several anatomical characteristics seen in both early-diverging ( basal) elasmosaurids and the Aristonectinae, an elasmosaurid

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

known primarily from Antarctica and New Zealand. In fact, early analyses recovered this taxon as a basal aristonectine. However, the alternative hypothesis that the aristonectine traits were

convergently evolved Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last comm ...

was also noted. In their 2025

phylogenetic analysis In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data ...

O'Keefe et al. instead recovered ''Traskasaura'' in a basal position within Elasmosauridae, as the

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to ''

Nakonanectes ''Nakonanectes bradti'' is an elasmosaurid plesiosaur of the late Cretaceous found in 2010 the U.S. state, state of Montana in the United States. It is one of the most recently known elasmosaurids to have lived in North America. Unlike other ela ...

''. These results are displayed in the

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

below:

References

{{Taxonbar, from1=Q134547214, from2=Q134560977 Elasmosauridae Sauropterygian genera Late Cretaceous plesiosaurs of North America Santonian genera Fossils of British Columbia Fossil taxa described in 2025