Birds that filled the niche left by the demise of dinosaurs.

1. Birds that filled the niche left by the demise of dinosaurs.

2. Some time in the Jurassic period, birds evolved from theropod dinosaurs. Birds and there relatives can be classified as Archosauria.(www.wikipedia.com) Neornithes are the taxon given to living birds, which can be divided into Palaeognathae and Neognathae. Introduction

3. During the Mesozoic, the Ichtyornithiformes and Hesperornithiformes shared the lineages of the neognathae. Birds which fly have various adaptations which allow them to fly, such as having a sternum to which a keel with the flight muscles are attached. Introduction

4. However the Archaeopteryx do not poses the sternal keel as well as the flightless ratite birds. Introduction

5. Before we explore the birds that filled the niche of dinosaurs, I explored the fossil records of aves. There are not many fossils of birds, because the hollow bones of birds are not likely to be kept preserved, there are however a few well preserved bird fossils. Fossil records of Aves

6. The oldest fossil found was of Archaeopteryx discovered in Germany,and in China a fossil was found about the same time that Archaeopteryx was discovered,called Confuciusornis, it however had no teeth. Fossil records of Aves

7. Birds from the Cretaceous era include Hesperornithiformes,which were toothed birds and were flightless swimmers. While the Ishthyornithiformes were carnivorous toothed flying birds. Fossil records of Aves

8. During the Eocene time period the Diatymidae were introduced and fossil evidence was found in Europe and in North America. The Diatymidae had reduced wings and they had a close resemblance to the living ratite birds. Fossil records of Aves

9. A. lithographica, is about 150million years old, and its fossil was discovered in Southern Germany A. lithographica is considered to be the earliest bird known and formed the transition between reptiles and birds. Archaeopteryxlithographica

10. In contrast to living birds Archaeopteryx had a “full set of teeth a flat sternum, a long bony tail, gastralia and three claws on the wing”(www.Wikipedia.com). It did however posed characteristics of modern birds such as the obvious been feathers, wings, reduced fingers as well as having a furcula. Archaeopteryxlithographica

11. The use of the birds feathers are not totally understood as it could have been used for flight , insulation or both. Archaeopteryxlithographica

12. KingdomAnimalia PhylumChordata ClassAves OrderGruiformes FamilyGastornithidae GenusGastornis (Herbert,1855) Classification of Gastornisgeiselensis

13. Fossil of G. geiselensis www.answers.com

14. G. geiselensis was a prehistoric bird,discovered by Gaston Plante, the bird was a carnivorous scavenger and hunter, that fed on small horses amongst other animals. It was about 1.75m tall. The closest living relatives to the Gastornis are the moorhens which fall in the Rallidae family. Gastornisgeiselensis

15. The fossil records of Gastornis are common in Germany at the “Geiseltal site” (www.Wikipedia.com), and in Northern America. At the height of 1.75m it was considered to be one of the largest animals, with an unusually large beak. Gastornisgeiselensis

16. The use of its large beak remains debatable and could have been used, but it could have been used for breaking nuts, hard shells and crushing bones. Due its unusual shape and size one would expect it to be a vegetarian apposed to a predator. Gastornisgeiselensis

17. They were flightless birds which occupied the Paleocene and Eocene periods of the Cenozoic, similar unrelated large birds which were the Phorusrhacoids, had South American origin as well as the Australian Dromornithidae. Gastornisgeiselensis

18. Fossils of some flightless birds

19. Raphuscucullatus (www.oxforduniversitymuseum.com) Other forms of pre historic birds

20. Kingdom: Animalia Phylum:Chordata Class: Aves Order:Columbiformes Family:Raphidae Genus:Raphus Species: Raphuscucullatus Classification

21. Fossils of Raphuscucullatus

22. The dodo went extinct in 1681,and inhabited the Mauritius islands. It was also a flightless bird and weighed approximately 23kg (www.bagheera.com) There is no complete fossil record of the dodo, only a few bones and primitive sketches. The Dodo

23. The dodo went extinct due to humans which colonized the islands of Mauritius. The introduction of other carnivorous animals such as feral cats and dogs and monkeys etc, also led to the demise of the dodo The Dodo

24. The dodo was last sighted in 168, and reached extinction by the end of the 17th century. (www.oxforduniversitymuseum.com) The Dodo