Showing posts tagged desmostylian

An Introduction to Desmostylians

The Desmostylia are an extinct group of marine mammals. They are both strange and enigmatic creatures known only from deposits of the Late Oligocene and the Miocene. Fossils assigned to four genera have been found in Japan and along the west coast of Mexico and the United States, to as far north as Washington.

Fossils of Desmostylus were first described in 1888 by Othniel Marsh, from marine deposits collected in Alameda County, California. The fossils were considered to represent Sirenians, and subsequent fossils found in Japan were interpreted as possibly being primitive Proboscideans (elephants) or Sirenians (sea-cows), though not without significant differences from either group.

Desmostylians are noted for having a number of bizarre and unique physical features, such as the tooth shown at right. The teeth and the pattern of wear in their enamel are unlike that observed in any modern mammal, and so no one is yet certain just what these short-tusked, shovel-jawed animals ate. This problem is compounded by the changes in coastal marine floras of the Miocene as kelp forests developed. The best evidence suggests they were herbivores, but anything beyond that is a guess…

(read more: UCMP - Berkeley)

(images: T - Nobu Tamura; BL - Darwin’s Bulldog, BM - Sarah Rieboldt, © Univ. of Cali. Mus. of Paleontology; BR - uncredited)

Desmostylus … is a monotypic extinct genus of herbivorous mammal of the family Desmostylidae living from the Chattian stage of the Late Oligocene subepoch through the Late Miocene subepoch (28.4 mya—7.250 Mya) and in existence for approximately 21.2 million years. Desmostylus was a large, hippopotamus-like creature about 1.8 m (6 ft) long which weighed about 200 kg (440 lb). It had a short tail and powerful legs with four hooves. Both the creature’s jaws were elongated and sported forward-facing tusks, which were elongated canines and incisors. Most likely amphibious, Desmostylus is thought to have lived in shallow water in coastal regions. Recent isotope work indicates that Demostylus most likely lived in freshwater or estuary ecosystems and ate aquatic freshwater plants. (via: Wikipedia)                 (image: Dmitry Bogdanov) View high resolution

Desmostylus

… is a monotypic extinct genus of herbivorous mammal of the family Desmostylidae living from the Chattian stage of the Late Oligocene subepoch through the Late Miocene subepoch (28.4 mya—7.250 Mya) and in existence for approximately 21.2 million years.

Desmostylus was a large, hippopotamus-like creature about 1.8 m (6 ft) long which weighed about 200 kg (440 lb). It had a short tail and powerful legs with four hooves. Both the creature’s jaws were elongated and sported forward-facing tusks, which were elongated canines and incisors.

Most likely amphibious, Desmostylus is thought to have lived in shallow water in coastal regions. Recent isotope work indicates that Demostylus most likely lived in freshwater or estuary ecosystems and ate aquatic freshwater plants.

(via: Wikipedia)                 (image: Dmitry Bogdanov)

Paleoparadoxia … is a genus of large, herbivorous marine mammals, a Desmostylian, that inhabited the northern Pacific coastal region during the Miocene epoch (20 to 10 million years ago). It ranged from the waters of Japan, to Alaska to the north, and down to Baja California, Mexico. Paleoparadoxia was about 2.4 m long. Paleoparadoxia is thought to have fed primarily on seaweeds and sea grasses. The jaws and the angle of the teeth resemble a backhoe bucket. Its bulky body was well adapted for swimming and underwater foraging, but not for extended deep-sea living or deep diving. Like the modern-day seal, Paleoparadoxia probably came on shore for breeding and basking in the sun. (via: Wikipedia)                  (image: Nobu Tamura) View high resolution

Paleoparadoxia

… is a genus of large, herbivorous marine mammals, a Desmostylian, that inhabited the northern Pacific coastal region during the Miocene epoch (20 to 10 million years ago). It ranged from the waters of Japan, to Alaska to the north, and down to Baja California, Mexico. Paleoparadoxia was about 2.4 m long.

Paleoparadoxia is thought to have fed primarily on seaweeds and sea grasses. The jaws and the angle of the teeth resemble a backhoe bucket. Its bulky body was well adapted for swimming and underwater foraging, but not for extended deep-sea living or deep diving. Like the modern-day seal, Paleoparadoxia probably came on shore for breeding and basking in the sun.

(via: Wikipedia)                  (image: Nobu Tamura)

Desmostylia (Greek for “bonded pillars”) is an extinct order of marine mammals which existed from the Arikareean age of the late Oligocene epoch (30.8 mya) to the Tortonian age of the late Miocene epoch (7.25 million years ago). Their dental and skeletal form suggests desmostylians were amphibious herbivores dependent on coastal habitats. Their name refers to their highly distinctive molars, in which each cusp was modified into hollow columns, so that a typical molar would have resembled a cluster of pipes, or in the case of worn molars, volcanoes. (This shows the close relationship between the Paenungulata, to which this group belongs, and the Tubulidentata)… (read more: Wikipedia) (image by Carl Buell) View high resolution

Desmostylia (Greek for “bonded pillars”) is an extinct order of marine mammals which existed from the Arikareean age of the late Oligocene epoch (30.8 mya) to the Tortonian age of the late Miocene epoch (7.25 million years ago). Their dental and skeletal form suggests desmostylians were amphibious herbivores dependent on coastal habitats. Their name refers to their highly distinctive molars, in which each cusp was modified into hollow columns, so that a typical molar would have resembled a cluster of pipes, or in the case of worn molars, volcanoes. (This shows the close relationship between the Paenungulata, to which this group belongs, and the Tubulidentata)… (read more: Wikipedia)

(image by Carl Buell)

Paleoparadoxia is a genus of large, herbivorous marine mammals that inhabited the northern Pacific coastal region during the Miocene  (10 - 20 mya). It ranged from the waters of Japan, to Alaska to the north, and down to Baja California, Mexico. Paleoparadoxia is thought to have fed primarily on seaweeds and sea grasses. The jaws and the angle of the teeth resemble a backhoe bucket. Its bulky body was well adapted for swimming and underwater foraging, but not for extended deep-sea living or deep diving. Like the modern-day seal, Paleoparadoxia probably came on shore for breeding and basking in the sun… (read more: Wikipedia) (image by Nobu Tamura) View high resolution

Paleoparadoxia is a genus of large, herbivorous marine mammals that inhabited the northern Pacific coastal region during the Miocene  (10 - 20 mya). It ranged from the waters of Japan, to Alaska to the north, and down to Baja California, Mexico. Paleoparadoxia is thought to have fed primarily on seaweeds and sea grasses. The jaws and the angle of the teeth resemble a backhoe bucket. Its bulky body was well adapted for swimming and underwater foraging, but not for extended deep-sea living or deep diving. Like the modern-day seal, Paleoparadoxia probably came on shore for breeding and basking in the sun… (read more: Wikipedia)

(image by Nobu Tamura)

Desmostylus, of the  Late Oligocene through the Late Miocene (28.4 mya — 7.250 Mya), was a large, hippopotamus-like creature of about 1.8 m (6 ft) long and weighed about 200 kg (440 lb). It had a short tail and powerful legs with four hooves. Both the creature’s jaws were elongated and sported forward-facing tusks, which were elongated canines and incisors. Most likely amphibious, Desmostylus is thought to have lived in shallow water in coastal regions… (read more: Wikipedia) (image by Nobu Tamura) View high resolution

Desmostylus, of the  Late Oligocene through the Late Miocene (28.4 mya — 7.250 Mya), was a large, hippopotamus-like creature of about 1.8 m (6 ft) long and weighed about 200 kg (440 lb). It had a short tail and powerful legs with four hooves. Both the creature’s jaws were elongated and sported forward-facing tusks, which were elongated canines and incisors. Most likely amphibious, Desmostylus is thought to have lived in shallow water in coastal regions… (read more: Wikipedia)

(image by Nobu Tamura)

The marine hippo-like mammal, Desmostylus hesperus by Dmitry Bogdanov View high resolution

The marine hippo-like mammal, Desmostylus hesperus by Dmitry Bogdanov