Archelon

George Reber Wieland in 1896 and named it Archelon ischyros, genus name from the Ancient Greek ἀρχη- (arkhe-) 'first/early', χελώνη (khelone) 'turtle', and species name from ἰσχυρός (iskhyros) 'mighty' or 'powerful'.

The holotype measures 352 cm (11.5 ft) from head to tail, with the head measuring 60 cm (2 ft), the neck 72 cm (2.4 ft), the thoracic vertebrae 135 cm (4.4 ft), the sacrum 15 cm (0.5 ft), and the tail 70 cm (2.3 ft). The largest specimen, Brigitta, measures around 460 cm (15 ft) from head to tail and 400 cm (13 ft) from flipper to flipper, and, in life, weighed around 2,200 kg (4,900 lb).

Archelon had a distinctly elongated and narrow head. It had a defined hooked beak which was probably covered in a sheath in life, reminiscent of the beaks of birds of prey. However, in the back, the cutting edge of the beak is dull compared to sea turtles. Much of the length of the head derives from the elongated premaxillae–which is the front part of the beak in this animal–and maxillae. The jugal bones, the cheek bones, due to the elongate head, do not project as far as they do in other turtles. The nostrils are elongated and rest on the top of the skull, slightly posited forward, and are unusually horizontal compared to sea turtles.

The carapace comprises on either side eight neuralia–the plates closest to the midline–and nine pleuralia–the plates that connect the midline to the ribs. The plates of the carapace are mostly uniform in dimensions, with the exception of the two pairs of plates corresponding to the eighth thoracic vertebra which are smaller than the others, and the pygal plate closest to the tail which is larger. Archelon has ten pairs of ribs, and, like the leatherback sea turtle but unlike other sea turtles, the first rib does not meet the first pleural.

Archelon belonged to the extinct family Protostegidae, a lineage different from today’s living sea turtles. In the past the giant leatherback turtle (Dermochelys coriacea) was thought to be its closest modern relative, but now scientists believe Protostegidae is a separate branch with no direct living descendants.

Archelon moved slowly across the seafloor and most likely consumed hard-shelled crabs, mollusks, and potentially even sponges because of its particularly hooked beak and crushing jaws. While swimming closer to the surface, it may have also eaten other creatures like nautiloids, squid, and jellyfish. Fish is another potential prey option, but Archelon's beak might have been more suited for shearing flesh. Archelon was probably able to create the strong strokes required for open-ocean migration and, if necessary, to flee from other marine predators thanks to its huge and powerful foreflippers.

In Rapunzel's universe, the opponent gets drenched when the sea turtle shoots a tiny stream or spiral of water out of its mouth.

Archelon was an obligate carnivore. The thick plastron indicates the animal probably spent a lot of time on the soft, muddy seafloor, likely a slow-moving bottom feeder. According to American paleontologist Samuel Wendell Williston, Archelon's jaws were adapted for crushing, implying the turtle ate large mollusks and crustaceans. In 1914, he suggested that the abundant, thin-shelled, bottom-dwelling Cretaceous bivalves–some exceeding 120 cm (4 ft) in diameter–would have easily been able to sustain Archelon.

Conversely, the beak may have been adapted for shearing flesh, and it might have been able to target larger fish and reptiles, as well as soft-bodied creatures, similar to the leatherback sea turtle, such as squid and jellyfish. Archelon, like other marine turtles, probably would have had to have come onshore to nest; like other turtles, Archelon probably dug out a hollow in the sand, laid several dozens of eggs, and took no part in child rearing. The right lower flipper of the holotype is missing, and stunted growth of remaining flipper bone indicates this occurred early in life.

Archelon may have been the result of attempted predation by a bird while a hatchling and trying to escape to the sea, bitten off by some large predator such as a mosasaur or a Xiphactinus, or was crushed off by larger adults while herding on the shore. However, the latter is unlikely as juveniles probably did not frequent the coasts even during breeding season.

Reproduction

As a sea turtle and reptile, Archelon would have laid eggs on sandy beaches. Like modern turtles, they were air-breathers and would have had to crawl onto land—likely at night—to lay eggs in sandy beaches. The sex of hatchlings was most likely decided by temperature, just as it is in current sea turtles.

Some Archelon fossils have been discovered in locations that indicate the turtles perished on the muddy seafloor while brumating, a type of reptilian slumber. Like contemporary sea turtles, Archelon would be wild and untamed; if left alone, they would be inquisitive and passively accepting of human presence. It is around the size of an automobile, and if provoked, its strong jaws might accidentally hurt people.

About 66 million years ago, during the K-Pg mass extinction that wiped off the non-avian dinosaurs, Archelon went extinct. Archelon was already under strain from a contracting seaway, lowering temperatures, and a high rate of egg and hatchling predation by smaller animals and land-dwelling dinosaurs, even if the asteroid impact was a significant contributing factor. Among the likely contributory elements are:

Their primary causes:

• Shrinking habitats as sea levels changed and the Western Interior Seaway receded

• Cooling climate narrowing suitable ranges

• Increased predation on eggs and hatchlings by other animals

• Competition with other marine reptiles

• Broad environmental disruptions at the end of the Cretaceous Mass Extinction event. 

A huge body of water known as the Western Interior Seaway divided North America in half during the Late Cretaceous. Archelon resided in what are now South Dakota, Wyoming, and North Dakota in the northern portion of this seaway.

• Movement Pattern: Full Migrant

• Individual Type: Solo

• Population Trend: Stable

• Population: 0

• Locomotion: Amphibious

• Habitat: Warm River; Cold River; Lukewarm River; Warm Pond; Cold Pond; Warm Lake; Cold Lake; Warm Littoral; Cold Littoral; Warm Intertidal; Cold Intertidal; Kelp Forest; Coral Reef; Barrier Reef; Guyot; Neritic Zone (Warm); Neritic Zone (Cold); Pelagic Zone (Warm); Pelagic Zone (Cold); Benthic Zone.

• Earth: 

  • Extinct: Belize; Canada; El Salvador; Guatamela; Mexico; United States (North Dakota; South Dakota; Wyoming)

All sea turtles are automatically tamed when hatched from an egg, as the survivor is always within 20 radius of the sac hatching. If the tortoise is somehow not tamed at birth, it can be tamed with a whip, any plant materials, buds, jellyfishes, seaweeds, or eggshells.

Seven Code Talkers events - 2000s

This tortoise fossil was excavated in Tres Hermanas, Rizal in deposits associated with the Laguna Formation by a team from UP NIGS and was described in 2007.

2020-2022 Renders

2023

• Physical Appearances

  • Their color palettes and schemes are still there, except for a few new ones.

• Others

  • There was no change to their behavior, diet, ecology, or skills for this species.

• 日本語: アーケロン (Arukeron)

• Maori: Arakerono

• 한국어: 아르켈론 (Areukellon)

• 中文: 古巨龜

• TBA

• https://en.wikipedia.org/wiki/Archelon

• https://species.wikimedia.org/wiki/Archelon

• https://species.wikimedia.org/wiki/Archelon_ischyros

• https://www.wikidata.org/wiki/Q632618

• https://www.biolib.cz/en/taxon/id60935/

• https://eol.org/pages/4522535

• https://www.gbif.org/species/4965003

• https://www.irmng.org/aphia.php?p=taxdetails&id=1310694

• https://paleobiodb.org/classic/basicTaxonInfo?taxon_no=128038

• https://dinopedia.fandom.com/wiki/Archelon

• https://ark.wiki.gg/wiki/Archelon

• https://www.britannica.com/animal/Archelon

• https://www.dndbeyond.com/monsters/5194901-archelon?srsltid=AfmBOordFrCpDDydCyaOKaSBNHff4oc3DJyekVKJSVSuiH4omcX41i_3

• https://www.deviantart.com/ognimdo2002/art/Archelon-862303609

• https://www.deviantart.com/ognimdo2002/art/Archelon-ischyros-2023-940488632