Encyclopaedia of Cryptozoology
This article is currently under construction.
To prevent edit conflicts with the user who added this template, please refrain from making any major edits to this article.
Many-finned sea serpent

The great sea centipede as represented in the Coleman-Huyghe system, drawn by Harry Trumbore.

System Heuvelmans system (1968), Coleman-Huyghe system (2003), Champagne system (2007), and Marshall system (2018)
Proposed scientific names Cetioscolopendra aeliani (Heuvelmans, 1965)
Mariascolopenda aelani (Woodley, 2008)
Other names Cetacean centipede, con rit, giant sea centipede great sea centipede, multi-finned sea serpent, multi-limbed sea serpent, segmented sea serpent
Sightings range Tropical and subtropical waters worldwide
Proposed identification Cetacean (Heuvelmans, 1965), indet. mammal (Champagne, 2007) crustacean (Shuker, 1995), polychaete worm (Bradshaw, 2007?), or myriapod (Woodley, 2008)

The many-finned or multi-finned sea serpent (Cetioscolopendra aeliani or Mariascolopenda aelani; French: multi-ailerons) is a Heuvelmans type of sea serpent, characterised by several lateral appendages described as fins or flippers.[1] It is equivalent to the great sea centipede of the Coleman-Huyghe system, the segmented or multi-limbed sea serpent of the Champagne system, and the giant sea centipede of the Marshall system. Sightings assigned to this category have occured in tropical and subtropical seas worldwide,[2] and the most recent possible sighting occurred in 1990.[3]

Heuvelmans rejected an arthropod identity for this type, instead suggesting an armoured cetacean descended from an Eocene basilosaurid, which he incorrectly believed were armoured.[1] Later cryptozoologists have been split between those in agreement with Heuvelmans,[4][5] and those who feel that a giant invertebrate, such as a crustacean, eurypterid, arthropleurid, or polychaete, is a more likely identity.[6][7] According to Karl Shuker, the many-finned is the most controversial of all Heuvelmans' types,[8] and some cryptozoologists have rejected it altogether.

Although most famously described by the Romans of late antiquity, who called it scolopendra, the great sea centipede was a characteristic sea monster of East Asian cultures, being described in several early Chinese and Japanese sources.[9] The type is sometimes called the con rit (Vietnamese: "centipede"), after a local Vietnamese name for such sea monsters. Heuvelmans believed the type to be mythologically significant, as the inspiration for the leviathan, lung, and dragon.[1]


As with most of Heuvelmans' types, the many-finned's existence as a distinct animal, regardless of its identity, has been criticised. Karl Shuker describes it as "perhaps the most controversial of Heuvelmans's nine sea serpent types",[8] Dale A. Drinnon as "the most dubious of all of Heuvelmans' categories".[10]

Dale A. Drinnon discounts it as a type, noting that, in spite of occasional denials, sightings could be explained by small whales or sharks swimming in lines; Drinnon claims that even long-necked sea serpents have sometimes been mistaken for "sea centipedes" in this way. He also argues that neither the Hạ Long Bay dragons nor the tompondrano conform to Heuvelmans' description.[11] Further, according to Drinnon...[12]

There is an additional problem that there is a variance in proportional widths per approximately similar lengths that can be as small as three feet or as broad as 15 feet, a difference of the greatest being five times the least estimated measurement. This is a difference of width to length ranging from 1/20 to 1/4, obviously the difference between how closely the individual finbacked animals are clustered together to create the "Row of fins" effect. With this sort of inconsistency of reports, it is excusable to wonder at the accuracy of other statements , such as "fins turned back to front".

Michael A. Woodley, while accepting the type's possible existence on the basis of the historical reports, the con rít, and the Narcissus sighting, takes issue with the liberality of the type's diagnostic characteristics, and suggests that the true number of sightings is much lower than Heuvelmans' estimate.[7]


Many cryptozoologists, including Bernard Heuvelmans, Loren Coleman, Patrick Huyghe, and Bruce A. Champagne, theorise that sea serpents in this category may be mammals, usually cetaceans, which Michael A. Woodley describes as "the closest thing approaching a consensus in cryptozoological circles regarding the identity" of the type. However, a minority, including Karl Shuker, Lance Bradshaw, and Woodley himself theorise that some form of giant invertebrate provides a closer match.[7]

Heuvelmans argued against an arthropod identity on account of the many-finned's size. Not only did it seem mechanically impossible for an arthropod to grow 60' long, he argued that the lack of any arthropods of a size intermediate between the common species and the giant cetacean centipede made such an identity unlikely, as "nature sometimes moves in leaps and bounds, but not such big ones as that".[1] Later cryptozoologists have suggested ways around this problem, as well as noting sightings in which the animal's "fins" are described as functional flippers, or true limbs, something inconceivable in a tetrapod.[7][6]


Loren Coleman and Patrick Huyghe defend the cetacean theory, arguing that "actual plating is not necessary for the Great Sea Serpent to look as it it has plates". They suggest that a cetacean with plates could be explained by either epizootic barnacles attached to the skin, or by plate-like dermal characteristics which have not been preserved in the fossil record. Alternatively, they theorise that the lateral "fins" are not bony plates but fin structures evolved for more efficient heat dispersal in tropical waters. Nevertheless, they regard the great sea centipede as the least likely of their own sea serpent types.[5] Bruce A. Champagne also classifies his "multi-limbed sea serpent" as a mammal, without specifying its exact proposed identity.[7]

Crustacean or chelicerate

One of the largest known modern arthropods is the long-legged Japanese spider crab (Macrocheira kaempferi), a crustacean (Source).

Larger species of the Silurian eurypterid Pterygotus were some of the largest free-swimming arthropods known (Source).

Isopods are ineffective free-swimmers (Source).

Especially in light of the con rit, Karl Shuker's preferred explanation for the many-finned, if it does exist, is a giant crustacean.[8] Shuker argues that the fins of the many-finned really are fins or flippers used as locomotory organs, and that, in life, the spines of the con rit globster would have sheltered a pair of soft-bodied limbs beneath, limbs which had rotted away by the time the carcass had been discovered. Shuker notes that multiple limbs, hard dorsal armour, and a soft body are all characteristic of crustaceans.[13]

As with all arthropod identities, the great size of many-finned, and of the con rit carcass, is a problem. No crustacean even approaching the alleged size of the many-finned is known from either modern times or the fossil record, although it may be theoretically possible for an aquatic crustacean to grow so large: unlike insects and arachnids, crustaceans breathe with gills, and their heavy bodies are buoyed by water, "hence the evolution of a giant aquatic crustacean is not wholly beyond the realms of possibility and, to my mind, offers the only remotely feasible explanation to Vietnam's anomalous con rit or sea millipede".[13]

Shuker has often been misquoted as believing that the many-finned may be either a marine centipede or a marine millipede.[6] On this subject, Shuker comments that "sea millipede and sea centipede are merely colloquial, non-taxonomic names for this cryptid, and that the identity for the con rit that I proposed [...] was a crustacean".[8]

Heuvelmans briefly considered, but ultimately rejected, the possibility that an evolved eurypterid, or sea scorpion, could explain the many-finned sea serpent.[6] Eurypterids occur in the fossil record from the Middle Ordovician to the Late Permian (~467—252 MYA), with no fossils ever found in post-Permian strata from the Mesozoic or the Cenozoic. They included in their numbers the largest known arthropod of all time, the 8' Devonian brackish-water Jaekelopterus, as well as somewhat smaller marine sea scorpions including Pterygotus, Carcinosoma, and Acutiramus.[1] Their bodies were segmented, and the eurypterine species had rudder-like tails, with two of their six limbs functioning as paddles: earlier free-swimming sea scorpions such as Pterygotus may have had a somewhat tolerable resemblance to descriptions of the many-finned, although their segments did not have paired limbs attached to them.[2]

However, by the time the group disappears from the fossil record, after a long decline, at the end of the Permian (~252 MYA), they had long since moved into brackish lagoons and freshwater habitats, and the only known remaining species were large, bulky sweep-feeders like Campylocephalus and Hibbertopterus, which lived in brackish or fresh water. These "sea scorpions" were incapable of free swimming, though they were able to walk on land. The last known swimming euryptine eurypterid was the much smaller Adelophthalmus, which seemingly went extinct in the Early Permian (~283 MYA).

Despite the large gap in the fossil record, Heuvelmans considered it plausible that eurypterids could have survived into the present day, citing the examples of similarly ancient animals like brachiopods, crinoids, and monoplacophorans, but found it difficult to believe that any eurypterid ever was or ever could be 60' long. Heuvelmans rejected a sea scorpion for the same reason he rejected all arthropods: the enormous size disparity between the many-finned and the largest known modern and prehistoric arthropods.[1] Karl Shuker concurs with Heuvelmans' rejection of a eurypterid identity, finding their post-Permian existence highly unlikely.[6]

Some other cryptozoologists have speculated that the many-finned could be a giant species of isopod crustacean. Woodley finds this an unlikely identity, as the largest known isopods are not talented free-swimmers.[7]


The Bobbit worm (Eunice aphroditois) is one of the largest known species of bristle worm. It may grow up to 10' in length.

Lance Bradshaw has theorised that the great sea centipede could be a giant, unknown species of polychaete worm, the larger species of which (such as the Bobbit worm Eunice aphroditois) can grow up to 10' in length in extreme cases.[14] More than 10,000 species of polychaetes have been described, mainly from marine habitats, although a minority of species are found in freshwater, and they display a diverse variety of lifestyles and morphologies. Also called bristle-worms, their tubular segmented bodies have a pair of fleshy protrusions, parapodia, on each segment, each one bearing chitinous bristles. Therefore, the morphology of the segmented, many-finned sea centipede is in agreement with a polychaete worm identity, except for its greater size. The polychaete theory could also explain the walrus-like head sometimes described, as Bradshaw suggests that the giant worm could have fangs like those of some smaller polychaetes, which might be mistaken for walrus-like tusks on such a big animal.[7]

Michael Woodley, while finding this identity more likely than that of an armoured cetacean, nevertheless argues that there are problems with it. He points out that larger polychaetes, like the Bobbit worm, tend to be burrowing ambush predators, unlike what is known of the many-finned sea serpent. Although an armour-plated polychaete may not need to hide under the sea-bed, no known polychaete has anything resembling armour plating, which Woodley counts as another issue with the theory.[7]


Arthropleura is history's largest known terrestrial vertebrate.

Although often referred to as a "sea centipede," few cryptozoologists have examined the possibility that the many-finned sea serpent could be a genuine marine myriapod, though Karl Shuker is often misquoted as supporting the idea. The giant myriapod theory was first seriously examined by Michael A. Woodley, who believes that this identity provides the closest match with the eyewitness data, which he admits is limited.[7]

Woodley, "fusing" the centipede and isopod identities, theorises that many-finned sea serpents, and especially the con rit, could be a living representative of the myriapod class Arthropleuridea, which disappears from the fossil record in the Early Permian. The most famous arthropleurid is Arthropleura (~345–295 MYA) itself, an inhabitant of swampy equatorial coal forests, which at 8' is the largest known terrestrial invertebrate. Arthropleura had a flattened body with around thirty segments, each one covered by three unusually-soft plates, and a small head. An aquatic or semi-aquatic freshwater lifestyle has sometimes been proposed for Arthropleura,[7][15] particularly given its lack of respiratory tracheal system, which leads Otto Kraus and Carsten Brauckmann to theorise that Arthropleura was an aquatic animal which breathed using its perforated ventral plates,[16] a theory which has since been criticised.[17] Arthropleura trackways are known from land, demonstrating that it was capable of terrestrial locomotion,[15] although the possibility that certain trackways were made in shallow water cannot be discounted,[17] and it may also have sought out freshwater for hydrostatic support during moulting.[18] Paleoenvironmental analysis suggests that Arthropleura may have favoured wet, open riverine habitats, where it was found with both aquatic and terrestrial taxa.[17]

The herbivorous Arthropleura, which probably fed on plant matter such as spores and young or dead lycophyte trees, is believed to have gone extinct in the Early Permian, when its wet habitat was desertified during the Carboniferous Rainforest Collapse. Woodley suggests that, to seek out new food sources, it or a more crustacean-like relative could have migrated to marine habitats, where hydrostatic water support and delayed sexual maturity may have allowed it to attain a much greater size even when atmospheric oxygen levels fell, eventually giving rise to the many-finned sea serpent. If the many-finned is usually an inhabitant of the deep sea, such an increase in size would not be entirely without precedent, as deep-sea gigantism is primarily observed in arthropods, particularly crustaceans, and other invertebrates. Woodley, arguing that Tran Van Con's carcass described by Krempf may be an acceptable type specimen, reclassified the many-finned sea serpent as Mariascolopenda aelani, ord. fam. nov., class Arthropleuridea, subphylum Myriapoda.[7]

The major problem with this theory is the lack of evidence for saltwater tolerance in Arthropleura, but Woodley argues that, given both its ancient semi-aquatic ancestry and the diversity of modern myriapods, it could either have retained or quickly developed a tolerance for saltwater.[7]

Notes and references

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Heuvelmans, Bernard (1968) In the Wake of the Sea-Serpents, Hart-Davis, ISBN 9780246643124
  2. 2.0 2.1 Eberhart, George M. (2002) Mysterious Creatures: A Guide to Cryptozoology, ABC-CLIO, Inc., ISBN 1576072835
  3. Champagne, Bruce A. "A Classification System for Large, Unidentified Marine Animals Based on the Examination of Reported Observations," Elementum Bestia: Being an Examination of Unknown Animals of the Air, Earth, Fire and Water (2007), Lulu Press, ASIN B001DSIB2W
  4. Champagne, Bruce A. "A Preliminary Evaluation of a Study of the Morphology, Behavior, Autoecology, and Habitat of Large, Unidentified Marine Animals, Based on Recorded Field Observations," Crypto Dracontology Special 1 (November 2001)
  5. 5.0 5.1 Coleman, Loren & Huyghe, Patrick (2003) The Field Guide to Lake Monsters, Sea Serpents and Other Mystery Denizens of the Deep, TarcherPerigree, ISBN 978-1585422524
  6. 6.0 6.1 6.2 6.3 6.4 Shuker, Karl P. N. (2016) Still In Search Of Prehistoric Survivors: The Creatures That Time Forgot?, Coachwhip Publications, ISBN 978-1616463908
  7. 7.00 7.01 7.02 7.03 7.04 7.05 7.06 7.07 7.08 7.09 7.10 7.11 Woodley, Michael (2008) In the Wake of Bernard Heuvelmans: An Introduction to the History and Future of Sea Serpent Classification, CFZ Press, ISBN 978-1905723201
  8. 8.0 8.1 8.2 8.3 Shuker, Karl P. N. ShukerNature: CONTEMPLATING THE CON RIT karlshuker.blogspot.com (16 February 2014) [Accessed 26 August 2020]
  9. Minakata Kumagusu "The Centipede-Whale," Nature, Vol. 58, No. 1511 (13 October 1898)
  10. Drinnon, Dale A. CRYPTOZOOLOGY ONLINE: Still on the Track: DALE DRINNON: Possible Identifications for some of Bruce Champagne's Independent Sea-Serpent Classification Categories forteanzoology.blogspot.com (25 May 2010) [Accessed 29 September 2020]
  11. Drinnon, Dale A. CRYPTOZOOLOGY ONLINE: Still on the Track: DALE DRINNON: Modifications to the Aquatic Cryptids Classifications as Proposed by Heuvelmans forteanzoology.blogspot.com (27 June 2010) [Accessed 29 September 2020]
  12. Drinnon, Dale A. (2009) "Amended Cryptozoological Checklist"
  13. 13.0 13.1 Shuker, Karl P. N. (1995) In Search of Prehistoric Survivors: Do Giant 'Extinct' Creatures Still Exist?, Blandford, ISBN 9780713-724691
  14. Bradshaw, Lance What Is The "Great Sea Centipede"? angelfire.com via web.archive.org [Accessed 29 September 2020]
  15. 15.0 15.1 McGhee, George R. (2018) Carboniferous Giants and Mass Extinction: The Late Paleozoic Ice Age World
  16. Kraus, Otto and Brauckmann, Carsten "Fossil Giants and Surviving Dwarfs: Arthropleurida and Pselaphognatha (Atelocerata, Diplopoda): Characters, Phylogenetic Relationships, and Construction," Verhandlungen des Naturwissenschaftlichen Vereins in Hamburg, Vol. 40 (2003)
  17. 17.0 17.1 17.2 Schneider, Joerg W. et al., "Euramerican Late Pennsylvanian/Early Permian Arthropleurid/Tetrapod Associations," New Mexico Museum Natural History Science Bulletin, No. 49
  18. Martino, Ronald L. & Greb, Stephen F. "Walking Trails of the Giant Terrestrial Arthropod Arthropleura From the Upper Carboniferous of Kentucky," Journal of Paleontology No. 83, Vol. 1 (2009)