Rhea mesopotamica facts for kids

Rhea mesopotamica was an extinct bird that lived a long time ago in South America. It belonged to the same group of birds as today's rheas, which are large, flightless birds found in South America, sometimes called suris or choiques. This ancient rhea lived in the southern part of the continent, in an area known as the Southern Cone.

Discovering Rhea Mesopotamica

Scientists first described Rhea mesopotamica in 2012. Two paleontologists, Federico L. Agnolín and Jorge I. Noriega, gave it the scientific name Pterocnemia mesopotamica at first. However, most scientists now agree that this bird belongs to the same group, or genus, as the modern rheas, so its name was changed to Rhea mesopotamica.

What is a Holotype?

When a new species is discovered, scientists choose one special fossil to be its "holotype." This fossil is like the official example of the species. For Rhea mesopotamica, the holotype is a piece of a right leg bone called a tarsometatarsus. Its official number is MACN-Pv 12743. You can find this important fossil at the Argentine Museum of Natural Sciences in Buenos Aires, Argentina.

Other fossil pieces were also found, like parts of other leg bones from both adult and young birds. These extra pieces help scientists learn even more about the species.

Where Were the Fossils Found?

The main fossils of Rhea mesopotamica were discovered in the ravines of the Paraná River. This area is near the city of Paraná, in a region of northeast Argentina called Mesopotamia. This place is known as the "type locality" because it's where the first and most important fossils of the species were found.

What Did It Look Like?

Scientists believe Rhea mesopotamica was a thin and relatively small bird. It probably looked a lot like the modern short-billed rhea or Patagonian rhea (R. pennata). One special feature of its leg bones was how the lower parts of the bone, called trochlea, spread out.

What Does Its Name Mean?

The name mesopotamica comes from the region where the first fossil was found: Argentine Mesopotamia. This is a common way for scientists to name new species, by using a place name.

Where and When Did It Live?

The fossils of Rhea mesopotamica were dug up from layers of rock that are part of the Ituzaingó Formation. These rock layers are sometimes called "Ossiferous Conglomerate" or "Mesopotamian." They can be seen in the ravines along the Paraná River in Argentina.

Scientists estimate these rocks are from the late Miocene epoch, which was about 7 to 5.5 million years ago. This time period is also known as the Huayquerian Age.

Another important fossil, a complete left leg bone, was found in a different part of Argentina, in the province of Mendoza. This fossil was found in the Aisol Formation, which is from an even older time, the middle to late Miocene. If this fossil also belongs to Rhea mesopotamica, it means the species lived for an even longer time, starting from the middle Miocene (Friasense Age).

See also

In Spanish: Rhea mesopotamica para niños