Family of the Week: The Metazoic Seals

The Metazoic family of seals, known as the Paraphocidae, are not really descended from modern seals. Rather, they come from weasel relatives, like otters. They somewhat resemble modern phocid seals, the external ears are not completely gone, but drastically reduced in size. The tail is either of medium length or very short. The nostrils close tightly shut to keep the water out, as can the ears. These seals have a third, clear, nictitating membrane that covers the eyes when they are underwater. The legs have been reduced to mere flippers. When landed, they move somewhat like turtles or crocodiles. Some are highly social species, living in groups of up to 100 individuals. While some are solitary, such as Monachitus. The eyes are large and round, the body is long, though it is somewhat longer in the species of Eufoedes than in any other seal. These seals also have the longest foreflippers in proportion to it's body than any other seal. They range in size from the 4-foot long-finned seal (Paraphoca pterogale) to the 50-60-foot long Megalophoca, which is perhaps the largest of all aquatic mammals in the Metazoic. All are aquatic, but not all live in the ocean. Unlike modern seals, but like some modern cetaceans, Mesophoca has made it's home in the Amazon River system.

The most interesting seals in this family is the kelp seal (genus: Gorgona). It is so-named because it lives among the kelp beds in the Pacific side of the USA. This seal does not swim in the usual horizontal fashion that other seals swim in. Instead, it normally swims in an upside-down vertical fashion so as to mimic the swaying strands of kelp it lives and feeds among. This makes the animal almost invisible to predators that may hunt it by sight, such as sharks. Gorgona is also a slow swimmer, inching along also making it seem like it is a part of the kelp beds. The only time the animal goes vertical is when it needs to surface, either to breathe or haul it's self back to land. These seals are also unique that they will sometimes snack on the strands of kelp. This provides the animal with a supply of iodine, a necessary mineral in reproduction. Though most of their diet consists of fish and urchins.

The largest seal, and probably the largest of all marine mammals in the Metazoic, is Megalophoca. This huge seal is the size of some modern whales. The males are the larger of the two, and never come to land. The smaller females may come on land to rear their pups, but that is it. All mating games take place in the ocean. This species, unlike modern seals, does not gather in large groups to raise their young. Females haul out alone on a beach and have their single baby. The baby is born helpless, unlike modern seals. The eyes are closed and they can barely move around on their own. By the time the baby is 4 weeks old, it will be ready to take it's first swim. The babies are born relatively small but grow fast. By this time, it is close to ½ the size of it's mother. Unlike modern seals, these seals are very helpful with their babies. With no males, or bulls, to hassle the young or push them around, females can dote on their pups as lovingly and caringly as any mother is with their young.

Eufoedes is the Metazoic's version of a leopard seal. This animal is built like a crocodile, and has much the same hunting habits. The disproportionately long flippers of this seal are ideal for maneuvering through the water after fish and other sea mammals, like Natopterus. This seal is a hunter, and the only member of this family to hunt such prey as other sea mammals. The head is somewhat large and elongate. The teeth protrude, as in crocodiles, and are very sharp and tough. Prey is killed much in the same manner modern leopard seals kill penguins, by slamming them on the surface of the water until their flesh is dismembered. This seal is long and slender in build and are mostly white in color. They prefer to wait underneath an ice flow for a prey animal to dip into the water and then the seal gives chase.

Mesophoca is the only seal to inhabit an inland river. Though many are familiar with the baikal seal, which inhabits Lake Baikal in Siberia, Mesophoca is a river animal. It is a long and slender seal, with short, round flippers and an otter-like head. The tail is medium-length and used to help paddle the animal through the water. They feed on fish, even the fearsome piranha. Often what this seal will do with piranha is attack from the backside and get a good grip behind the gills and violently shake the fish underwater until it has beheaded the fish. They are not very social seals, living mostly in couples, rather than in large groups.

Seals are mostly predators. Each one having it's own menu but basically the main diet consists of meat, such as fish, and even other mammals. But seals themselves may fall prey to other predators as well. Sharks are a main concern. For some species, even the greatest of all Megalophoca, they have to worry about sea genets (Thalassogenetta), which will kill not only adult seals, but their pups as well. Thalassogenetta particularly relishes Megalophoca, ripping into their chest and abdominal cavity with extreme and terrifying ease, and dismembering the giants in a manner of minutes. On land, seals have to contend with land-based predators as well. Though seals in the Metazoic are very alert and quick to respond to predatory advances, they are sometimes taken by dogs, deinognathids, mongooses, and Ailurocyonids. The pups may sometimes fall prey to large predatory oceanic bats like Acerictus. Mesophoca is one of many prey items of Deinognathus, which will sneak up and kill the animal as it rests on the riverbank.

Comments

Popular posts from this blog

The Making of Lemuria?

New Changes to Old Names

How Cities Affect Evolution