Genyornis

Kingdom: Animalia

Phylum: Chordata

Class: Aves

Order: Anseriformes

Family: Dromornithidae

Genus: Genyornis

Species: G. newtoni

Temporal Range: Late Pleistocene

The beak of Genyornis was a large, flightless bird that lived in Australia, over two meters in height, they became 50 thousand years ago. Many other species became extinct in Australia around that time, coinciding with arrival of humans.

Description

Genyomis was a large flightless bird, considerably taller and heavier  than the modern ostrich or emu. It had powerful legs and tiny wings and probably most closely resembled its living relatives duck and geese. But instead of having webbed feet and a duckbill, Genyornis had large hoof-like claws on its toes and a big beak. Like modern birds, it had no teeth but relied on gizzard to assist its digestion. Genyornis was over two meters tall and would weighed from 220-240 kilograms. Eggshell fragments have been recovered in sand dune deposits. The eggs of Genyornis were large, up to 1.6kg, almost twice the volume of emu eggs, smooth in texture and less elongate than emu eggs.

Habitat

Genyornis fossils are known from Lake Callabonna, Baldina Creek, Mt. Gambier, Salt Creek and Naracoorte Caves in South Australia, and from Wellington Caves and Cuddie Spring in New South Wales. Eggshell fragments have been found in dune deposits in South Australia and footprints, possibly those of Genyornis, have been found in Pleistocene dunes in Southern Victoria.
Genyornis had a wide distribution in a variety of habitats but seems to have preferred open forest and savannah-grasslands to more and more closed forest habitat preferred by earlier mihirungs. Eggshell fragments have been found in sand dunes and Genyornis may have used these dunes as nesting sites. A shift  to grasslands and increasing aridification in some areas may have favored the emu in some regions which may then have replaced Gyornis in local faunas.

Diet

The Diet of the whole Dromornithidae family has been the subject of much debate. Many palaeontologists are convinced that dromonithids were mainly if not exclusively herbivorous. Dromornithids lack a hooked beak, as in raptors and have hoof-like rather than recurved claws on their feet. Analysis of eggshells supports an herbivorous diet. Dromornithids are also found in large numbers in some deposits, unlike carnivores which at the top of the food chain, are generally very rare. A minority view holds that dromornithids were to some degree carnivorous, citing the huge size of the beak.
The diet of Genyornis has been determined by any direct evidence although  it appears to have been herbivorous. Fossils of Genyornis have been found with pebbles in the gizzard region, which are unknown in carnivores. Gastroliths wold have been used to help break up its food, as they do in other herbivorous birds. It is quite possible, given its anatomy and discovery of gastroliths, that Genyornis was herbivorous but the larger Bullockornis and Dromornis had a more varied diet.

Evolution 

Once thought to be ratites, dromornithids are now believed to be either within Anseriformes or just basal to  it. Recent revisions of the taxonomy of other large, flightless birds place these taxa within Anseriformes. All of these large birds, including the dromornithids, have a short dentary symphysis and a dorsally directed pterygoid process on the quadrate, unusual features not related to flightlessness. This revision is still debated, although many feel that the general placement of at least dromornithids, somewhere near the base anseriform radiation has merit.

Life Cycle

The eggs of Genyornis have been found in sand dune deposits which have also preserved the eggshells of emus. These dunes may have served as breeding grounds for both species, Hole similar to those made by mammalian canine teeth have been found in some Genyornis eggshell fragments. The size of these holes suggests that the predators were either Tasmanian devils or eastern quolls, both of which are known from the dune deposits.

Extinction

Human impact and climate change are the main two reason behind the extinction of this birds. A study has been performed in which more than 700 Genyornis eggshell fragments were dated. Through this, it was determined that Genyornis declined and became extinct over a short period. That short period is so short that climate change can not be the only and definitely the main reason behind that extinction. According to research studies, it is confirmed that the extinction of this birds in Australia was due to human activity rather than climate change. Human killed this bird for meat and they also take their eggs for meal. many eggs were found burned in fire (they are well cooked) which means human took those as meal.