Another speculative radiodont lost to the fossil record (check out my first entry here). This is the False Ammonite, Pseudammonites ptilobrachiones, a filter-feeder that sweeps plankton and small fish from the water with its massive, broom-like Great Appendages. Much like a hermit crab, the creature’s soft body is protected inside the discarded shell of another animal, in this case an ammonite. The False Ammonite’s home floats at the surface of the ocean thanks to a symbiotic siphonophore, Megaera deformibaccata, that inhabits the inner chambers. Siphonophores are relatives of jellyfish that form vast connected chains of individual animals known as zooids. Many zooids are highly modified to serve specific tasks within the colony such as reproduction, prey-capture, and bouyancy. The striped, pink tentacles dangling from the aperture of the shell in this illustrations are Megaera’s fishing tentacles and the orange pear-shaped blobs are gas-filled "float" zooids.
To the right of the False Ammonite is another hypothetical filter-feeding radiodont, the Sun Drifter, Medusocola silvadorsum. Drifters inhabit the stomachs of jellyfish, where they gain protection and free transportation. Most Sun Drifters harbor a small colony of Gardner Crabs, Demeter hortulanus. These crustaceans feed on algae that they cultivate on the back of their Drifter. Like a human gardener, they constantly tend and prune their harvest, brushing it clean with their furry antennae and keeping it free of other herbivores.
Those strange, vertically-oriented creatures are Thief Fish, Scutoculus longinares. They hang out under the False Ammonite, using their large, fan-like tail fins to keep themselves upright so they can steal bits of food from the great appendages of the radiodont and from the tentacles of its siphonophore partner. Thief fish have transparent bubbles of hard skin covering their eyes to protect them from the fine, stinging hairs that cover the False Ammonite’s arms and from the jelly’s tentacles.
Visually this piece was inspired by a painting in the book The New Dinosaurs by Dougal Dixon, a Scottish paleontologist and educator. The New Dinosaurs postulates what dinosaurs, pterosaurs, ichthyosaurs, and other Mesozoic animals might have revolved into had they not gone extinct at the end of the Cretaceous. Dixon had written an earlier book, After Man, about how animals might evolve millions of years in the future after humans have gone extinct. After Man and The New Dinosaurs (along with Dixon’s less popular Man After Man, about the possible future evolution of humans) are considered by many to be the foundations of the modern genre of speculative evolution.
The entry that influenced my creature was the Kraken, Giganticeras fluitarus, a massive speculative ammonite that feeds with nets of stinging tentacles much like a jellyfish or siphonophore.
The Thief Fish were inspired by the real life Barreleye Fish, Macropinna microstoma, an unusual deep-sea fish that has elongated eyes which can rotate straight up to scan the water above it. It is thought that the barreleye feeds by stealing food from the tentacles of siphonophores, deep-dwelling relatives of jellyfish. Live footage of Macropinna revealed that the fish has a transparent shield over its eyes which may protect them from siphonophore stings.
|Barreleye. Image Courtesy: Wikimedia Commons|
The Sun Diver was inspired by Phronima, a genus of crustaceans that ride around in the hollowed-out gelatinous bodies of barrel-shaped creatures called salps. While Phronima eats the insides of its host, leaving just an empty, protective jelly-shell, the Sun Drifter leaves its host alive, to serve as a living transport.