Studying Beaked Whales entangled in Tuna nets in the northwest Indian Ocean.

Beaked Whales, Ziphiidae, spend the majority of their time in deep oceanic waters, spending most of their lives beyond the continental shelves, and little at the surface. This makes them one of the least well-understood groups of Cetaceans, or Mammals of any kind. Some species have few, if any, sitings ar sea, being known almost exclusively from bodies washed ashore in varying states of decomposition. Because of this, the taxonomy of Beaked Whales is less well-established than is the case for most Mammal groups, with new species and nomenclature revisions being published every few years. 

Studying Whales caught as bycatch offers a cost-effective way to study poorly understood Cetacean populations, providing insights into populations which can help shape conservation policies. Such data collection is often accomplished by training fishermen themselves as citizen scientists. Drift gillnets are widely used many parts of the world to target Tuna, but are also noted for the large amount of large-Vertebrate bycatch they produce. In the northwest Indian Ocean drift gillnets are widely used by the fishing fleets of Iran and Pakistan, presenting a threat to Whales in this area, but also presenting an opportunity for scientists to gather data on these Animals.

In a paper published in the journal Zoology in the Middle East on 13 February 2025, Muhammad Shoaib Kiani of the Institute of Marine Science at the University of Karachi, Mohsen Rezaie-Atagholipour of the Qeshm Environmental Conservation Institute, Rab Nawaz and Muhammad Moazzam of the World Wide Fund for Nature - Pakistan, Bushra Shafiq also of the  Institute of Marine Science at the University of Karachi, Haleh Ali Abed of the Midaf Nature Conservation Society, and Koen Van Waerebeek, also of the Qeshm Environmental Conservation Institute and of the Centro Peruano de Estudios Cetológicos, present the results of a long-term study of Beaked Whale entanglements in Tuna gillnets in Iranian and Pakistani waters.

A citizen science program was established in Pakistan in 2012, in which fishermen on pelagic gillnet Tuna vessels were trained to collect data on Cetacean bycatch. In Iran reviews of mass media at local and national levels, looking for Cetacean-related stories, have been carried out since 2018, and a series of interviews of fishermen was carried out in 2022.

Kiani et al. discovered eight incidents in which entangled Cetaceans could be identified as Beaked Whales in the waters of the Gulf of Oman and Arabian Sea, two in Iranian territory, five in Pakistani territory, and one in international waters.

The first recorded incident happened on 10 February 2015, when fishermen on board the Pakistani vessel Al-Azaan discovered a live Beaked Whale caught in a gillnet they had deployed 95 km to the west of the Swatch (the undersea canyon formed where the Indus River enters the ocean) and 177 km off the coast of Sindh, an area where the seafloor is about 1.5 km deep. 

Based upon video evidence, this Whale was estimated to be 5-6 m long, and slender with a slightly protrudent melon (mass of adipose tissue on the forehead), and a long snout without protruding teeth. This Animal lacked the scars associated with tooth-raking typically seen in male Beaked Whales, and is therefore assumed to have been a female.

The Whale had a brownish-grey dorsal surface, slightly paler on the head, and had a large, Dolphin-like fin about two thirds of the way along its body. This is, along with its location in the tropical Indian Ocean, is considered to be consistent with a Longman’s Beaked Whale, Indopacetus pacificus. This species was first described in 1928 from the skull of a Whale found in Queensland Australia in 1882, with a second skull being found on the shore of Somalia, East Africa, in 1955. For a long time, these two specimens were all that was known of this species, however, recent studies have established that Whales washed up on the shores of the Philippines, Maui (Hawaii), Taiwan, Myanmar, the Andaman Islands, South Africa, and Japan, previously identified as Southern Bottlenose Whales, Hyperoodon planifrons, were in fact Longman’s Beaked Whales, and based upon this data, 65 sightings of live Whales in the  Indian and Pacific oceans have been assigned to the species.

The Whale encountered by the Al-Azaan became entangled in a net as it was being retrieved, allowing the crew to release it without apparent harm by cutting away part of the net. This process took about 30 minutes, and while the Whale is thought to have been unharmed, one of the fishermen received minor injuries.

(a)-(h). Successive steps in gillnet disentanglement operation of a Longman’s Beaked Whale, Indopacetus pacificus, in Pakistani waters. Note the head with moderately bulbous melon (e), (h), long rostrum (f), (g), (h) tubular in dorsal view (h), limited linear scarring (e) and large falcate dorsal fin (f, g). Selected frames were taken from a video. Kiani et al. (2025).

The second recorded incident happened on 31 March 2017, when an un-named Pakistani vessel encountered a 4 m long Whale 383 km off the coast of Pakistan, again in the Swatch area, an area where the sea slightly more than 3 km deep. 

This Whale had a distinct, but non-bulbous melon, a long slender snout, and a low, sub-triangular dorsal fin. The skin of the Whale was a uniform grey, slightly darker towards the tail, and it had no visible scarring of any type. It was not possible to identify this Whale to species level, but it was probably a member of the genus Mesoplodon, possibly Deraniyagala’s Beaked Whale, Mesoplodon hotaula, or Ginkgo-toothed Beaked Whale, Mesoplodon ginkgodens, although this species has never been recorded in the Indian Ocean, or even Ramari’s Beaked Whale, Mesoplodon eueu, although this species tends  to lighten towards the tail, and is a cold-water species, never previously recorded in the western Indian Ocean north of Mozambique. 

The third incident was recorded in August 2017, when a fisherman from Bandar-e-Konarak on the coast of Sistan and Baluchestan Province, Iran, sent a video to the Iranian National News Agency, IRIB News, showing a Whale entangled in a gill net. This incident is thought to have happened in the waters of Iran’s Exclusive Economic Zone, and probably close to Bandar-e-Konarak. 

The Whale could be seen to blow, suggesting that it was alive and breathing. It appears to be a Beaked Whale with no visible teeth. The bulbosity of the melon cannot be determined from the video. The fluke (tail) of the Whale can be seen, and from comparison to the arm of a fisherman, is estimated to be between about 140 cm wide, which would equate to a Whale 4.7-4.9 m in length. The fluke also lacks a median notch, confirming that the Animal is a Ziphiid.

An unidentified middle-sized Beaked Whale, with a melon of unclear bulbosity, net-entangled within Iran’s Exclusive Economic Zone waters off Sistan and Baluchistan Province, northern Gulf of Oman, in August 2017. (a), (b) Flukes without central notch and tailstock; (c) the only registered blow and vague view of the head. Both Mesoplodon sp. and Indopacetus pacificus would be possible. Kiani et al. (2025).

The fourth incident occurred on 18 January 2018, when a small-to-medium sized Beaked Whale was recorded trapped in gillnet 474 km from the coast of Pakistan, an area where the sea is slightly under 3.2 km deep. This Whale was 3.5-4.5 m long, with a medium length snout and a non-bulbous melon and no central notch on its fluke; its colour and/or markings could not be determined due to poor light. This is consistent with it being a member of the genus Mesoplodon. The Pakistani fishermen who encountered this Whale were able to disentangle it from their nets, and report if swam away in good condition. 

The fifth incident occurred on 19 March 2019, when two Beaked Whales, interpreted as a mother and calf, became entangled in the same gillnet off Churna Island, 96 km from the coast of the Pakistani Mainland. The waters here are shallow, at 295 m.

The calf was described as the size of an adult Common Bottlenose Dolphin, making it 3.0-3.5 m in length, while it was not possible to estimate the size of the larger Whale. The smaller Whale had a dark grey upper surface,  and a whitish underside. It had a short snout, and no sign of a bulbous melon, its dorsal fin hooked, no notch could be seen in the tail. These Whale are also interpreted as belonging to the genus Mesoplodon. The fishermen reported successfully disentangling both Whales.

The sixth recorded incident happened in February 2022, when Iranian fishermen reported encountering a Whale caught in a drift gillnet 1300 km off the coast of Bandar-e-Beris in eastern Sistan and Baluchestan Province. Video footage of the incident shows a medium-sized Beaked Whale with a medium-length Dolphin-like beak, and a non-steeply sloping melon, consistent with a member of the genus Mesoplodon. The video also shows that the Whale has two apical or slightly sub-apical mandibular teeth, indicating that it was male, as well as a dark eye-patch, an almost straight mouth, and a small, slightly hooked tail. The length of the Whale is uncertain, but it appears to be about 4.5-5.5 m.

An unidentified Mesoplodon sp. bycaught in far offshore waters of the northern Arabian Sea, 1300 km from Bandar-e-Beris at the eastern side of Iran’s Sistan and Baluchestan Province, in February 2022. (a), (c) Two erupted (sub)apical mandibular teeth indicate an adult male. (b) Dolphin-like, medium-length rostrum, gently sloping melon and smallish dorsal fin. Kiani et al. (2025).

The final incident happened in early June 2023, when a large Beaked Whale became entangled in a drift gillnet in the coastal Iranian Gulf of Oman, about 37 km from the port of Chabahar in eastern Sistan and Baluchestan Province. This Animal was clearly an adult male, with numerous took-rake scars and erupted apical teeth. It was estimated to have been 5.8-6.0 m in length, with an erect, Dolphin-like dorsal fin, and way brownish grey in colour with a lighter head. This is interpreted as being consistent with either a Longman’s Beaked Whale, Indopacetus pacificus, or a Cuvier’s Beaked Whale, Ziphius cavirostris. 

An adult male Beaked Whale being liberated after accidental entanglement in Tuna gillnet in coastal waters of the Gulf of Oman, some 37 km from Chabahar, Iran, in early June  2023. (a) Large body size with two erupted teeth at the apex of the mandibula; (b) a tall, erect, falcate, Dolphin-like dorsal fin, a moderately long and well-defined rostrum; (c) with numerous tooth rakes on anterior body; and (d) some degree of bulbosity in the melon. The morphology of the Beaked Whale is congruent with Indopacetus pacificus, but Ziphius cavirostris cannot be excluded. Kiani et al. (2025).

The first of these incidents is regarded as the first record of Longman’s Beaked Whale, Indopacetus pacificus, in Pakistani waters, with incidents five and seven representing potential additional sightings. A beached individual assigned to the species was recorded in Gujarat State, India, in 2014, making the Pakistan entanglement the second record of the species in the northwest Indian Ocean. Previously a skull has been recorded from the coast of Somalia in 1955, a member of the species was sighted from Socotra Island, Yemen in 1971, and another in the waters of the southern Bay of Bengal in 2009. Five Longman’s Beaked Whales have been recorded as bycatch from Sri Lanka, although these have been disputed, and fourteen sightings and a stranding recorded from the Maldives. 

Incidents two, four, six, and possibly five represent the first records of Mesoplodon sp. in Iranian and Pakistani waters, although none of these specimens could be confidently identified to species level. 

Drift gillnets are considered to be one of the most significant anthropogenic threats to Whales, although evidence to support this is absent in many areas. Kiani et al.'s study shows entanglement is a clear threat to Beaked Whales in the northwestern Indian Ocean, as while all of the reported Whales were freed, it is likely that a greater number of Whales were not released safely, and therefore not reported.

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Echinoderes semprucciae: A new species of Kinorhynch from a macerating Neptune Grass environment in the eastern Mediterranean.

Kinorhynchs are tiny (generally less than 1 mm) worm like Animals largely found in marine sediments, for which reason they are sometimes known as 'Mud Dragons'. They appear to be ubiquitous members of the interstitial meiofauna (Animals that live between sediment grains) in shallow marine habitats, but have been studied in relatively few locations. However, not all Kinorhynchs are sediment-dwellers, with members of the group having been found living on a wide range of Algae, marine Plants, and Animals.

In a paper published in The Eutopean Zoological Journal on 3 February 2024, Adele Cocozza di Montanara of the Department of Science and Technology at the Parthenope University of Naples, Alberto González-Casurrubios of the Department of Biodiversity, Ecology and Evolution at the Complutense University of Madrid, and Diego Cepeda of the Centre for Research on Biodiversity and Global Change at the Autonomous University of Madrid, and the Department of Life Sciences at Alcalá University, describe a new species of Kinorhynch from a macerating Neptune Grass environment off the coast of Ischia Island in the western Mediterranean Sea.

Neptune Grass, Posidonia oceanica, is a form of Seagrass endemic to the Mediterranean, where it forms vast meadows in the photic parts of the sea (i.e. those areas where sufficient sunlight penetrates to allow photosynthesis). Seagrasses are important habitat-forming organisms, and a wide range of Animals, including Kinorhynchs are adapted to life in these meadows. However, as well as meadows, Seagrasses also form areas called 'macerating Seagrass detrital bottoms', where large volumes of decomposing leaves and rhizomes accumulate, typically below the photic zone, forming an important marine carbon sink. Whilst these environments have been known since the 1950s, very little attention has been paid to them or the fauna which live there, to which end Cocozza di Montanara et al. have begun a project to study the fauna of the macerating Seagrass detrital bottom environment of the Regno di Nettuno Marine Protected Area, along the coast of Ischia Island off the western coast of Italy.

Study area at 65–80 m depth along the northwestern area of Ischia Island (western Mediterranean Sea). Cocozza di Montanara et al. (2025).

The new species is placed in the genus Echinoderes, and given the specific name semprucciae, in honour of Federica Semprucci of the University of Urbino Carlo Bo, for acting as co-supervisor for Adele Cocozza di Montanara's PhD and supporting and guiding her research on meiofauna. The species is described from two specimens, both collected on 19 June 2020 near Ischia Island, an adult female, collected at a depth of 80 m, and an adult male collected at a depth of 70 m.

Line art illustrations of Echinoderes semprucciae. (a) Ventral view of a female based on holotype (NHMD-1177723). (b) Dorsal view of a female based on holotype (NHMD-1177723). (c) Dorsal view of segments 10–11 of a male based on paratype (NHMD-1177722). Abbreviations: ac, acicular spine; gcoI, type 1 glandular cell outlet; LA, lateral accessory; LD, laterodorsal; ltas, lateral terminal accessory spine; lts, lateral terminal spine; LV, lateroventral; MD, middorsal; ML. midlateral; ne, nephridiopore; pa. papilla; PD. paradorsal; ps, penile spines; SD, subdorsal; ss, sensory spot; t, tube; Vl, ventrolateral; VM, ventromedial; number in abbreviations indicates the corresponding segment. Cocozza di Montanara et al. (2025).

The two known specimens of Echinoderes semprucciae are 202 μm (female) and 193 μm (male) in length, with a retractable mouth cone surrounded by oral styles. This retractable mouth is mounted on an organ called the introvert, which has six concentric rings of scalids and 10 longitudinal sectors defined by the arrangement of primary spinoscalids. Behind the head is a neck section, then a trunk comprising eleven segments, with spines on segments four, six, eight, nine, and eleven; the two spines on segment eleven being elongated to form a pair of tail-like structures.

Light micrographs of female holotype (NHMD-1177723) (a)-(d), (g) and male paratype (NHMD-1177722) (e), (f) of Echinoderes semprucciae. (a) Ventral overview. (b) Head, dorsal view. (c) Head, ventral view. (d) Ventral view of segments 5–6. (e) Lateral view of segments 5–8. (f) Detail of penile spines. (g) Ventral view of segment 11. ltas, lateral terminal accessory spine; lts, lateral terminal spine; lvs, lateroventral spine; lvt, lateroventral tube; pa, papillae; ps, penile spines; te, tergal extension, number after abbreviation indicates the corresponding segment, sensory spots are marked with dashed circles and type 1 glandular cell outlets with closed circle. Cocozza di Montanara et al. (2025).

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Plectranthias raki: A new species of Perchlet from the Maldives.

The term 'Perchlet' applies to a wide variety of small Perciform Fish. The genus Plectranthias is a member of the Serranidae, the family which also includes Sea Bass and Groupers, amongst other groups. It currently contains 66 described species from mesophotic reef environments in the Atlantic, Pacific, and Indian Oceans. Plectranthias are small Fish, typically 5-10 cm long with the largest species reaching about 20 cm, which live in holes or crevices, from where they ambush small, mobile invertebrates. The small size and cryptic nature of Plectranthias means that they are not well studied, with most species described from a very small number of specimens.

In a paper published in the journal ZooKeys on 16 January 2024, Bart Shepherd of the Steinhart Aquarium at the California Academy of Sciences, Hudson Pinheiro of the Department of Ichthyology at the California Academy of Sciences, and the Center for Marine Biology at the University of São Paulo, Ahmed Najeeb, also of the Department of Ichthyology at the California Academy of Sciences, and of the Maldives Marine Research Institute, Claudia Rocha, again of the Department of Ichthyology and of the Department of Microbiology at the California Academy of Sciences, and Luiz Rocha, once again of the Department of Ichthyology at the California Academy of Sciences, describe a new species of Plectranthias from the Kuramathi Outer Reef on Rasdhoo Atoll in the Maldives.

The new species is described from two specimens collected by hand-netting at a depth of 118 m, in December 2022, and confirmed as a new species by gene-sequencing. It is named Plectranthias raki, where 'raki' means 'feeling shy to confront people' in the Dhivehi language which is spoken in the Maldives.

Living specimen (not retained) of Plectranthias raki photographed at 110 m depth at Dhaalu Atoll, Maldives. Luiz Rocha in Shepherd et al.  (2025).

The two specimens of Plectranthias raki are 66.15 and 70.41 mm long, and pinkish white in colour with a series of irregular orange-red patches, these being more red towards the tail and more yellow towards the head. Both have dorsal fins with fifteen rays, anal fins with seven rays, pectoral fins with thirteen rays, and tail fins with nine upper rays and eight lower rays.

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Two new species of Solenogastre from the Gulf of Mexico.

Solenogastres (Aplacophora) are a unique group of Molluscs which have vermiform bodies (i.e. are 'worm-shaped'), lack shells (although some have calcareous sclerites), and have a greatly reduced mantle and foot. This anatomy long led evolutionary biologists to conclude that Solenogastres represent a 'primitive' state for Molluscs, and they were interpreted as an early-branching clade with a sister-group relationship to all other Molluscs. Modern genetics-based taxonomy has reviewed this slightly, showing that the Solenogastres are the sister group to the Chitons (Polyplacophora), a superficially Gastropod-like group which have segmented shells and lack internal torsion, with these two combined forming the out-group to all other Molluscs. There are currently about 300 species of described Solenogastres, although it is thought that their true diversity is much higher. Solenogastres are notoriously difficult to locate and identify, particularly for non-specialists. Most species are less than 5 mm in length, many live infaunally in marine sediments, some of them on the oceans deep-abyssal plains, while others live epifaunally or on the bodies of Corals of Hydrozoans.

In a paper published in the journal ZooKeys on 31 September 2024, Carmen Cobo of the Department of Invertebrate Zoology at the Smithsonian National Museum of Natural History, William Farris, Chandler Olsen, and Emily McLaughlin, of the Department of Biological Sciences at the University of Alabama, and Kevin Kocot, also of the Department of Biological Sciences at the University of Alabama, and of the Alabama Museum of Natural History, describe two new species of Solenogastre from the Gulf of Mexico, collected from Autonomous Reef Monitoring Structures.

Autonomous Reef Monitoring Structures are standardised structures used to sample marine life on reefs. They are made up of multiple stacked flat plates which mimic a complex reef-environment. These structures are screwed onto a reef-surface, where they attract settling benthic organisms, and can be collected at a later date, without damaging the overall reef-structure. The Autonomous Reef Monitoring Structures examined by Cobo et al. where placed on reefs in the Gulf of Mexico by the Research Vessel Point Sur in May 2019, and collected in August 2021.

One of the Autonomous Reef Monitoring Structures deployed in the Gulf of Mexico from which Solenogasters were collected. Cobo et al. (2024).

The first new species described by Cobo et al. is placed within the genus Dondersia and given the specific name tweedtae, in honour of marine biologist Sarah Tweedt, who collected the specimens used in the study, for her outstanding work studying invertebrate biodiversity using Autonomous Reef Monitoring Structures. It is described from a single specimen from an Autonomous Reef Monitoring Structure deployed at a depth of 82 m.

The single known specimen of Dondersia tweedtae is about 14 mm in length and 0.55 mm wide at the mid-body, although in life the Animal expanded and contracted its body as it moved. It is bright pink in colour, with a dorsal keel made up of seventeen distinct bright yellow lobes. It has a smooth appearance, with a covering of scale-like sclerites, of which there are three different types. 

Habitus of Dondersia tweedtae. (A) Field photographs of the holotype showing the contractions and extension range (usnm 1718003). (B) Photograph of the holotype preserved in ethanol B’ detail of the lobes of the dorsal keel. Star indicates the anterior end of the Animal. Cobo et al. (2024).

The second new species is placed within the genus Eleutheromenia and given the specific name bullescens, where 'bullescens' derives from the Latin 'bullescere', meaning 'to bubble', in reference to the protrusions on the dorsal keel of the Animal. The species is described from two specimens collected from an Autonomous Reef Monitoring Structure placed at a depth of 82 m within the Gulf of Mexico, about 100 km to the west of the structure from which Dondersia tweedtae was collected.

The specimens of Eleutheromenia bullescens are 10-12 mm in length and 0.5-1.0 mm in width at their midsections, although again, in life these Animals expanded and contracted their bodies as they moved. They were light orange in colour, with a dorsal keel made up of numerous lobes, and a covering of spines formed from hollow sclerites, some of which are hook- or harpoon-shaped.

Habitus of Eleutheromenia bullescens. (A), (A’) Field images of the Holotype (USNM 1718004) (B), (B’) Field images of the paratype (USNM 1718005). (C( Paratype in 95% ethanol. (D) Detail of the dorsal lobes in the holotype (decalcified mid-body region). Images were captured using Olympus DSX100 optical microscope with anti-halation and fast HDR adjustments; brightness 0016 to 0022, texture 50-71, contrast 36-50. Star indicates the anterior end of the animal. Arrow indicates detached lobes and their 'pedunculi'. Cobo et al. (2024).

Both Dondersia tweedtae and Eleutheromenia bullescens have distict dorsal keels, something not generally found in Solenogastres, combined with brighter colouration than is typical for the group. Despite this, they were confirmed by both morphological and genetic analysis to be members of distantly related groups. Furthermore, the structures of the dorsal keels are quite different in the two species, strongly suggesting that this is a result of convergent evolution, rather then recent common ancestry. the reason for this is unclear, though Cobo et al. note that in the absence of shells, Solanogastres have adopted a range of other defence strategies, including mimicry, crypsis, autotomy, production of defensive chemicals, or the retention of exogenous biochemically active compounds and cnidocytes (the stinging cells of Cnidarians) from their prey. They further note that the lobes which make up the dorsal keel of Eleutheromenia bullescens contained a number of cells which appeared to be derived from another organism, including one possible cnidocyte.

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An Early Cretaceous Plesiosaur from Ellesmere Island, Canada.

The Plesiosaurs were a group of Marine Reptiles which appeared in the Triassic and persisted till the End of the Cretaceous. The group obtained a global distribution during the Jurassic, when the supercontinent of Pangea broke up and high global temperatures led to large areas of the world's continents being submerged. However, towards the end of this period the situation had changed, when falling sealevels led to many ocean basins becoming isolated, many groups of large Marine Reptiles becoming extinct, and faunal communities becoming provincialized in different ocean basins. Plesiosaurs are not thought to have been strongly affected by the End Jurassic Extinction Event, but their fossil record is poor during the Early Cretaceous, limiting our understanding of the group during this interval.

In a paper published in the journal Acta Palaeontologica Polonica on 2 December 2024, Lene Delsett of the Natural History Museum at the University of Oslo, adam Smith of Nottingham Natural History Museum, Stephen Ingrams of Llandudno, and Simon Schneider of the Cambridge Arctic Shelf Programme, describe a Plesiosaur from the Early Cretaceous Deer Bay Formation of Ellesmere Island in the Canadian Arctic.

The specimen was excavated in 1952 by the Danish geologist Johannes Christian Troelsen, however, while he mentioned it in a report of his expedition to the area, it was never formally described. It was sent to the University of Copenhagen, where it appears to have undergone some preparation work by a student working under the supervision of curator Eigil Nielsen, and possibly subsequent curator Niels Bonde. The remains were subsequently packed into a series of wooden crates, one of which was opened and examined by Adam Smith in 2005. This box were subsequently misplaced, possibly during the flooding which affected the museum in 2011, but was subsequently relocated by curators Bent Lindow and Arden Bashfortht, and its contents transferred to a draw s in the main fossil Vertebrate collection. Two further crates, labelled '“Reptile Creek, Troelsen’s office' were discovered in 2019, and found to contain several girdle elements of the Plesiosaur specimen. Another box was discovered in the collections of the Zoological Museum in 2020, containing what was labelled as part of a 'Scoresbysund Plesiosaur', but which clearly belong to the Elis Island specimen. Another box, labelled 'NHMD 189689' contained some fragmentary ribs which also appeared to belong to the Elis Island specimen, but in the absence of any documentation were not included in the study.

The surviving specimen comprises 22 non-consecutive vertebrae from the cervical, dorsal, and caudal regions, hundreds of rib fragments, partial girdle elements, all four propodials, and several distal limb elements. All these elements are worn, and the larger elements mostly fragmentary. Delsett et al. were able to assign the specimen to the Cryptoclidid genus Colymbosaurus, but, due to the fragmentary nature of the specimen and a limited amount of overlapping material with other specimens, were not able to determine whether it belonged to either of the two previously described species in the genus, or from a different, as yet undescribed species. 

Selected vertebrae of Plesiosaur Colymbosaurus sp. NHMD 189834 from Ellesmere Island, Nunavut, Canada, upper Berriasian–lower Valanginian. (A) Cervical vertebra (centrum C), in articular (A₁), dorsal (A₂), ventral (A₃), and lateral (A₄) views. (B), (C) Pectoral vertebrae. (B) Centrum E in articular view. (C) Centrum D, in articular (C₁) and lateral (C₂) views. (D) Sacral? rib. (E)–(G) Dorsal vertebrae. (E) Centrum H, in articular (E₁) and lateral (E₂) views. (F) Centrum M (dorsal?) in articular view. (G) Centrum I in articular view. (H), (I) Caudal vertebrae. (H) Centrum O in articular view. (I) Centrum P in articular (I₁) and lateral (I₂) views. The letters used in the element names are written on the individual elements. Delsett et al. (2024).

Previous known specimens of Colymbosaurus spp. have been described from Spitsbergen, southern England and western Russia, so the Elis Island specimen represents a significant range expansion for the genus. The genus was therefore present in two separate ocean basins, the Boreal Arctic and Boreal Atlantic, which were connected by two seaways, one running between Norway and Greenland beneath the modern North Atlantic, and one in present day western Russia.

Map with Cryptoclidid occurrences in the Northern hemisphere. (1) Ellesmere Island; (2) Spitsbergen; (3) Great Britain; (4), (5) Russia. Delsett et al. (2024).

The Boreal Ocean during the Late Jurassic and Early Creraceous has been considered to have been an ecologically depleted environment, with most of the described fossils being Bivalves, Ammonites, and Belemnites. However, Cryptoclidid Pleisiosaurs were large, predatory Animals, reliant on Fish for at least part of their protein intake, which implies that these must also have been present. Delsett et al. suggest that, few deposits from this interval are noted for their fossil content, at least part of the apparent absence of many Animal groups may be because most studies of these deposits have concentrated on their stratigraphy rather than their faunal diversity, and therefore useful index fossils, such as shelled Molluscs tend to have been described, whereas less stratigraphically useful fossils, such as Plesiosaurs or Fish, may have been overlooked.

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