Casterolimulus
Scientific Classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Order: Xiphosura
Genus: Casterolimulus
Type Species: Casterolimulus kletti
Described by Holland, Erickson & O'Brien, 1975
Current Park Population: (17; all adults; 8 male, 9 female)
Park Diet: frozen fish, shellfish, shrimp, and squid.
Natural Diet: mollusks like small clams, crustaceans, annelid worms, other benthic invertebrates, bits of fish, algae, and carrion.
Lifespan: 20 years
Habitat: Rivers, Streams, Waterways, Ponds, Lakes, Creeks, Floodplains, Swamps, lagoons, Estuaries, and Coastal Shores.
Native Ecosystem: Western North America, on what was then an island continent known as Laramidia. Hell Creek Formation, Fox Hills Formation, Alberta, Canada, Colorado, Montana, North Dakota, South Dakota and Wyoming, USA, 68-66 Million Years Ago, Maastrichtian Stage, Late Cretaceous.
Breeding Season: March through July, with the peak spawning activity occurring around the evening new and full moon high tides in May and June.
Eggs Laid: 3,650-4,000 eggs.
Hatching Time: Two-Five Weeks.
Danger Level: 1 out of 10.
Summary: Horseshoe crabs are one of the oldest living species on Earth, with fossils dating back as far as 445 million years ago, dating back from the Earliest Hirnantian in the Ordovician. The group has hardly changed in appearance and the most notable difference between ancient and modern forms is that the abdominal segments in present species are fused into a single unit in adults. Although there are four living species in modern times, some extinct species lived in freshwater environments like Casterolimulus.
Description: They are bronze yellow in color, sometimes algae grow on their shells and resemble Atlantic Horseshoe Crabs.
Classification: It is a member of the family Limulidae, and is placed as a close relative of Victalimulus from the Early Cretaceous of Australia.
Dentition and Diet: Because they have no mandibles or teeth, they crush hard food between their legs covered with bristles before passing it to their mouth, and a gizzard that contains sand and gravel. They dig through sand and gravel in search of worms and any organic debris. It will move the substrate around almost nonstop in its search for food.
Growth and ontogeny: "Development begins when the first egg cover splits and a new membrane, secreted by the embryo, forms a transparent spherical capsule" (Sturtevant). The larvae form and then swim for about five to seven days. After swimming, they settle and begin the first molt. This occurs about 20 days after the formation of the egg capsule. As young horseshoe crabs grow, they move to deeper waters, where molting continues. Before becoming sexually mature around age 9, they have to shed their shells some 17 times. In the first 2–3 years of their life, the juveniles stay in shallow coastal waters or freshwater waterways.
Reproduction: Spawning tends to occur in the intertidal zone and is correlated with spring tides (the highest tides of the month). They emerge at the shoreline in late spring to spawn, with the males arriving first. The smaller male grabs onto the back of a female with a "boxing glove" like structure on his front claws, often holding on for months at a time. Often several males will hold on to a single female. Females reach the beach at high tide. After the female has laid a batch of eggs in a nest at a depth of 15–20 cm (6–8 in) in the sand, the male or males fertilize them with their sperm.
Interactions with other species: Often ignored by the large dinosaurs, adults, young, and eggs are prey to predators like Pectinodon, Dromaeosaurus, Acheroraptor, Anzu, Trierarchuncus, Quetzalcoatlus, and juvenile T. Rex, predatory fish, sharks, Didelphodon, Borealosuchus, Thoracosaurus, Champsosaurus, Brachychampsa, Axestemys, Palaeobatrachus, Scapherpeton, and Habrosaurus.
Extinction: Although Horseshoe Crabs will survive for millions of years, most species went extinct Casterolimulus was one of them near the end of the Cretaceous during the K-PG Mass Extinction Event due to acidification in the freshwater areas and waterways and changes in the temperatures.
Danger Tip: Horseshoe crabs are harmless. They're not dangerous. They don't have teeth or jaws, and they're not venomous. Their tails might look scary, but they're used to help turn the crab back over if it gets flipped upside down on the beach.
Significant Events: On the Team's Final Day of their First Rescue Mission, the team comes upon a group of Casterolimulus crawling along the river alongside amphibians, Habrosaurus and Scapherpetons, and various fish. They were captured in nets to be transported to the Park. They now reside in the Hell Creek Forest Building.
Hell Creek Forest Building Aquarium: This large tank houses most of the Hell Creek Fishes and aquatic life replicating the freshwater waterways, visitors can view them with underwater thick glass panel viewing. Casterolimulus are often found crawling around the tank's sandy bottom.
Conclusion: Horseshoe Crabs are quite well-known and bizarre in modern times and have helped people in the medical field due to the properties of their blue blood, although they are in decline. Casterolimulus represents a true "Living Fossil" that's been around without changing appearance for a million years and they would still be around today for Prehistoric Park visitors to observe and enjoy these ancient creatures.
The Field Guide might take a long time, like structuring and writing descriptions of the creatures, but also my time in college and spending time with my family. So you can suggest additional information quotes, descriptions, and natural or speculative behaviors for the prehistoric animals that I can edit and you send your suggestions either in reviews or Private Messages.
Examples: Inferring what the toons are doodling on the sketches or snarking quotes.
Negative, hateful, and spam comments are not allowed and will be reported, this is WildExpert24 signing off.