This cute sea creature is actually named after the "ancestor of all monsters"?

Typhoeus, known as the father of all demons, is a Titan giant who symbolizes storms in Greek mythology. As the most powerful demon, he has great powers and a terrifying appearance. It is said that lightning and fire are sprayed from Typhoeus' head, his lower body is a huge snake, his body is covered with feathers and has a pair of wings. Wherever he walks, he will leave behind hellfire that destroys everything. After Typhoeus was born, he stirred up trouble and committed all kinds of evil, and was eventually sealed by Zeus with a trick.

Typhon, a demon in Greek mythology, has a strange and terrifying appearance. Image source: Fandom

The ancient biological monster named after Typhon, "Typhloesus wellsi", is also a mysterious and elusive animal, and is known as one of the "three great monsters of paleontology" along with the Tully monster and the Neyek worm. They have no ancestors and no descendants, and their appearance is extremely strange and confusing.

The Typhon monster has been discovered for decades, and there are many well-preserved specimens, but humans haven't even figured out which phylum it belongs to, let alone its sub-classification. But recently, a possible true identity of it has slowly surfaced...

The original reconstruction of the Typhon monster shows a fusiform body, a tail fin, and muscle segments similar to those of vertebrates, with an "eye" in the middle, which looks very strange. Image source: Falmouth University Research Repository (FURR)

Part 1

Good teeth make everything delicious

The Typhon monster lived in the tropical shallow sea north of the equator during the Carboniferous period 324 million years ago. Its fossils were found in the Bear Valley Limestone in Montana, USA. Their bodies are fusiform, with a maximum length of 9 cm. There is a tail fin supported by two sets of perpendicular fin rays at the back of the body. Apart from this, there are no other organs on the outside. Inside, they have a foregut equivalent to the human mouth, esophagus and stomach, and a midgut equivalent to the human small intestine. Below the midgut is a disc-shaped, obviously black organ, temporarily called the ferrodiscus. Scientists currently do not know what the purpose of this organ is, only that it has a high iron content.

In the fossil of the Typhon monster, a distinct black “iron disk” can be seen in the center, with a thinner channel in front of the disk and a large black tissue surrounding it. Image source: Reference [2]

At first glance, the Typhon monster is a strange, round, worm-like creature with no mouthparts for hunting and no paired fins or dorsal fins for balance.

According to common logic, such a creature would have difficulty in moving, let alone hunting. However, conodont fossils are often found in the body of the Typhon monster. Conodonts are free-swimming predatory vertebrates similar in shape to lampreys, with certain swimming abilities. So, how did the Typhon monster catch conodonts?

On September 21, 2022, an article published in Philosophical Transactions of the Royal Society B: Life Sciences showed new discoveries about the Typhon monster. Scientists found possible traces of phosphorylated muscle tissue and suspected radula in the fossils of the Typhon monster.

The radula is a structure unique to mollusks, located at the base of a part called the "lingual protrusion" at the bottom of the mouth. It is composed of tiny teeth called "lingual teeth" that can cut food like a saw and then deliver it directly to the esophagus.

The structure suspected to be the radula in the Typhon monster fossil is an organ similar to a tongue protrusion identified in the foregut region. The bottom of the tongue protrusion has a reticular and fibrous structure, and the top includes two rows of small calcareous teeth in a ribbon shape, which is very similar to the radula structure of mollusks.

Although the typical radula of living mollusks has three rows of small teeth, divided into central teeth and lateral teeth on both sides, there are some species, such as aplacophors without shells, sea snails and purple snails that eat jellyfish and anemones, which have no central teeth and only two rows of teeth. Their radula structure is similar to that of the Typhon monster, which supports the argument that the structure of the Typhon monster belongs to the radula, and the Typhon monster with a radula is naturally classified as a mollusk.

The radula of a mollusk (radular teeth) is attached to an odontophore and can be turned out of the mouth to chew food. Image source: Barnegat Bay Shellfish Radula diagram

The suspected radula of the Typhon monster is located behind the mouth opening, deep in the body. Because the radula grows in the mouth, this shape is interpreted as an inverted proboscis structure, that is, this structure is similar to a long, tubular proboscis, but it is retracted into the esophagus upside down, so the radula is also received in the middle of the body.

Although this form is somewhat bizarre to humans, it is not new among mollusks, which are famous for their ingenuity:

Specialized echinoderm hunters, the Tonnidae family has a large, extendable, tubular mouth and is a natural predator of echinoderms such as sea cucumbers and sea urchins. Some larger species also catch fish. They first paralyze their prey with saliva containing sulfuric acid, then open their huge mouths to swallow it whole.

A quail snail (right) preys on a sea cucumber (left), swallowing it whole using its giant, tubular mouth that can be stretched into a trumpet shape. Image source: Wikiwand

The Hydatina sea slugs also have a similar structure, with a tube-like proboscis that is usually retracted into the body, in almost the same position as the radula of the Typhon monster. The proboscis of the Hydatina is enclosed in a body cavity filled with fluid. When hunting, the Hydatina adjusts the hydraulic pressure of the proboscis to turn it inside out, probe into the calcium pipes of the Cirratulidae worms, bite them to death with the radula at the top of the mouthparts, and then swallow them.

By observing the predation behavior of living mollusks, we can imagine the predation process of the Typhon monster: the front digestive tract containing teeth is forcefully and quickly everted through hydraulics and other means, so that the teeth are on the outside, rushing towards the prey and preying.

The mouthparts of the bubble snail (the long black tube in front) are usually retracted into the body and turned out when in use, similar to the Typhon monster. Image source: Hydatina physis (Linnaeus, 1758) - The Sea Slug Forum › hydaphys

The radula (upper left), mouthparts (upper right) and reconstruction of the Typhon monster. Its reconstruction image is a whale, but it is actually a sea slug. Annotations in the figure: ra.-radula, pr.-snout, to. teeth, fd. iron-containing disc structure, Mo. mouth, v.kl. abdominal keel structure, f.gt foregut, m.gt midgut, vi.ca visceral sac. Image source: Reference [3]

Part 2

Swim fast, eat well

In order to catch moving prey, the Typhon monster also needs certain athletic and perceptual abilities.

In the fossils of the Typhon monster, there are large areas of phosphorus deposits on the back of the body, forming a broad outline of two groups of tissue blocks tilted in opposite directions. The high content of phosphorus indicates the presence of muscles, which are likely to represent muscle tissue used for propulsion.

At the same time, a pair of protruding fleshy skirt-like objects were found on the ventral side of the Typhon monster, which were inferred to be forked near the preoral area, indicating that the preoral area was huge and might be an important auxiliary area for capturing prey.

This fleshy skirt around the mouth may be equivalent to the "oral curtain" of the living sea slug Cladobranchia. The oral curtain is a circle of surrounding structure around the mouth of sea slugs. Some are large and some are small. Some have sensory papillae, which function as chemical receptors and can sense the location of prey through them.

A reconstruction of the Typhon monster preying on conodonts shows that its extended mouthparts are composed of an outer trumpet-shaped structure and an inner radula complex. There is a circle of yellow protrusions under the body that forks near the mouth, which may have a sensory function. Image source: The Guardian

At the same time, if it is classified as a mollusk, another unknown structure of the Typhon monster is also explained: the large central fusiform area that wraps the midgut and part of the foregut is equivalent to the visceral sac of the mollusk, and the posterior fins on the rear side have a certain degree of similarity with the fin-like structures of sea slugs in the gastropod class such as Carinaria and Pterosoma. The remaining structure may be gelatinous to help the animal float in the water, using its flexible body and protruding hind fins to propel itself in the water.

Therefore, the Typhon monster was most likely a swimming, planktonic, shell-less gastropod mollusk, or sea slug in a broad sense, just like the modern sea cow - a small, highly transparent marine planktonic gastropod mollusk that is similar to fish in body morphology and movement, and is one of the best examples of convergent evolution.

The living Phylliroe is a gastropod very similar to fish, which propels itself in the water by swinging its tail and preys on jellyfish and other creatures. Image source: Deep Sea News

The living Carinaria is a large, transparent floating gastropod that can reach 50 cm in length. It has a tail and body structure similar to that of the Typhon monster. The part that is equivalent to the "iron plate" of the Typhon monster is the digestive tract that stores food. Image source: Francesco Turano

Part 3

The "monster" was born, and the ancestors tried their hand

But even if the Typhon monster is classified as a gastropod, its more specific classification cannot be determined, because similar planktonic shellless gastropods did not appear until the Triassic period, and the origin of various living sea slugs can only be traced back to the Cretaceous period.

Therefore, even if the Typhon monster was an ocean-going gastropod, it would not be the ancestor of modern planktonic gastropods, but just an early attempt by gastropods to swim.

In any case, as the earliest possible attempt at "sea slug"ization among gastropods, the morphology of the Typhon monster has greatly deviated from the snail appearance of ordinary gastropods with thick shells, and has evolved into a strange appearance that scientists cannot classify. Modern sea slugs are even more bizarre than the Typhon monster.

They are like Typhon, with electric lights on their heads, snake-like ventral feet in the lower body, and covered with "hair". Some of them have a pair of wings. When attacked, they will emit acid that will make people retreat. The Atlantic sea slug spreads its wings and soars in the ocean like a dragon, the tasseled sea slug swallows like a lion, the cystoglossus can photosynthesize, and the Alicia sea slug can be decapitated and reborn...

The Atlantic sea slug (Glaucus atlanticus) of the family Poseidonidae is like a dragon in Western mythology, preying on jellyfish on the water surface and taking their stinging cells into its body for its own use. Image source: Wikipedia

The lion's mane sea slug (Melibe leonina) of the oceanic sea cow family has a mouth that is disproportionately large for its body. It has a mouth curtain and sensory tentacles on its mouth, which can be closed to catch shrimps, crabs and other creatures. Image source: Monterey Bay Aquarium

Even though Typhon has been sealed and the Typhon monster has become extinct, their spirit and evolutionary direction have not disappeared. These sea slugs active in modern oceans with bright colors, strange appearances, and special habits are their successors and miniatures. Later, we will follow the swimming style of the Typhon monster into the magical world of sea slugs and explore these strange and magical creatures.

Produced by: Science Popularization China

Author: Komeichiren

Producer: China Science Expo

The article only represents the author's views and does not represent the position of China Science Expo

This article was first published in Science Popularization China

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