Extinct Animal Series: La Meseta Formation

This is part 6 of our series exploring the extinct animals from different regions of the world. Part 4 studied Extinct Animals in Russia, whereas we explore Extinct Animals of Africa in Part 5. 

We launched this series around three months ago with North America. As mentioned in the first part, since greedy humans have created a soundless apocalypse in the wild with numerous species disappearing from the earth’s face, we intend to cherish and celebrate these inferior (according to humans) species from different regions. We explored South America in Part 2. We saw extinct species in Australia in Part 3.

Today, we are picking up a specific location and not another continent for our piece.

Fossils in La Meseta Formation

The La Meseta Formation is a sedimentary sequence deposited around 50 million years ago. The formation is located on Seymour Island, Antarctica.

It is an around 1,827 feet thick sequence of poorly consolidated siltstones and sandstones.

Fossil content

La Meseta Formation is remarkably rich in fossils. Among mammals, the Trigonostylops and meridiungulata Antarctodon have been discovered in the formation.

 It is famous for its penguin fossils, for example, the two genera Palaeeudyptes and Archaeospheniscus. Other bird fossils include Dasornis, a family of pseudo tooth birds. 

Let’s explore the extinct animals in the fossils. 

  1. Antarctodon: Antarctodon is a dead family of meridiungulatan mammals from 63 million years ago. It is a basal astrapotherian that lived in Seymour Island. At that time, Antarctica was still attached to South America, where most of the astrapotherians were located. 
  2. Liano’s Whale: Llano’s whale is a genus of dead toothed baleen whales from Antarctica’s Late Eocene. The type varieties, Llanocetus denticrinatus, reached gigantic proportions. The juvenile specimen reached an estimated 26 ft in length; a second, unknown species, known only from three isolated premolar teeth, reached an estimated total body length of up to 39 ft. Like modern baleen whales, Llanocetus totally lacked baleen in its jaws. It was apparently a suction feeder like the modern beaked and pygmy right whales. 
  3. Archaeospheniscus wimani: Archaeospheniscus wimani is an extinct variety of penguins. It was the tiniest species of penguins, being around 30 to 33 inches high or about a Gentoo penguin’s size. It is also the oldest known species of its genus, as its remains were found in Middle Eocene strata (34 MYA) of the La Meseta Formation on Seymour Island, Antarctica. It is distinguished from a fair number of bones.
  4. Palaeeudyptes klekowskii: Palaeeudyptes klekowskii, also known as the colossus penguin, was a variety of the extinct penguin genus Palaeeudyptes. Until recently, it was considered to have been about the size of its congener Palaeeudyptes Antarcticus, which would mean it was somewhat more massive than the modern emperor penguin. However, a new study shows it was, in fact, almost twice as tall. It is distinguished from an extensive collection of fossil bones from the Late Eocene (34 MYA) of the La Meseta Formation on Seymour Island, Antarctica. P. klekowskii was at first not recognized as a different species. Despite the coexistence of two so closely related species of similar size as Palaeeudyptes Gunnari and P. klekowskii seeming somewhat unlikely, the amount of fossil material proposes that the two species are diagnosably distinct.
  5. Anthropornis: Anthropornis is a sub-specie of giant penguin that lived 45 million years ago, during the Late Eocene and the earliest days of the Oligocene. It reached 5 ft 11 in in height and 90 kg in weight.

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