Prehistoric birds

[Spalea]

Let us begin a new topic about the prehistoric birds which appeared after the first mammals, except if we consider that the avian-dinosaurs were in fact some birds...

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Discovered in China in 2002 Jeholornis was one of the first bird, having lived at the Early Cretaceous from 140 to 125 millions years BC. It was in fact a long tailed-avalian, 70 cm long and weighing 20 pounds. A little bit more evolved than the famous Archaeopteryx... Reply

[Spalea]

" Phorusrhacids, colloquially known as terror birds, are an extinct clade of large carnivorous flightless birds that were the largest species of apex predators in South America during the Cenozoic era; their conventionally accepted temporal range covers from 62 to 1.8 million years (Ma) ago.

They ranged in height from 1–3 m (3 ft 3 in–9 ft 10 in) tall. Their closest modern-day relatives are believed to be the 80-centimetre-tall (31 in) seriemas. Titanis walleri, one of the larger species, is known from Texas and Florida in North America. This makes the phorusrhacids the only known large South American predator to migrate north in the Great American Interchange that followed the formation of the Isthmus of Panama land bridge (the main pulse of the interchange began about 2.6 Ma ago; Titanis at 5 Ma was an early northward migrant). It was once believed that T. walleri became extinct in North America around the time of the arrival of humans, but subsequent datings of Titanis fossils provided no evidence for their survival after 1.8 Ma. However, reports from Uruguay of new findings of relatively small forms dating to 18,000 and 96,000  years ago would imply that phorusrhacids survived there until very recently (late Pleistocene). "

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[Spalea]

I repeat what it was said at #1, but with an other illustration:

Discovered in China in 2002 Jeholornis was one of the first bird, having lived at the Early Cretaceous from 140 to 125 millions years BC. It was in fact a long tailed-avalian, 70 cm long and weighing 20 pounds. A little bit more evolved than the famous Archaeopteryx... 

*This image is copyright of its original author

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[Spalea]

Discovered in Patagonia (Argentina) in 1999, described in 2007, this bird enjoyed the biggest bird's skull that ever existed: 71,6 cm long. Should have lived during the Miocene. Belongs to the Phorusrhacinae family (essentially inside the South American continent), the "terror birds" having reached up to 3m20 high. This bird could have also been a fast runner.
 

*This image is copyright of its original author

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[Spalea]

Aepyornis , "Elephant bird" by Zdenek Burian
Weighing up to 540 kilos, endemic specy of Madagascar, extinct at least since the 11th century...

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[Spalea]

" Argentavis magnificens was among the largest flying birds ever to exist, quite possibly surpassed in wingspan only by Pelagornis sandersi, which was described in 2014. A. magnificens, sometimes called the Giant Teratorn, is an extinct species known from three sites in the Epecuén and Andalhualá Formations in central and northwestern Argentina dating to the Late Miocene (Huayquerian), where a good sample of fossils has been obtained. "

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[Spalea]

" Fossil kept its feathers, and colors, for 130 million years ?


Photo: The fossilized remains of Eoconfuciusornis, a beaked bird with no teeth, still contains traces of its original color. (Image: Xiaoli Wang)

An exquisitely preserved fossil found in China still contains the original biological compounds that gave a 130-million-year-old bird its shading and color. The find extends the timeframe in which scientists thought these substances can be preserved.

In a new paper published in the Proceedings of the National Academy of Sciences, researchers from North Carolina State University, the Chinese Academy of Sciences, and Linyi University, show evidence of original keratin and melanosome preservation in the fossilized remains of Eoconfuciusornis, a crow-sized bird that lived in China some 130 million years ago. It’s the oldest fossil ever discovered to still contain traces of these color-giving molecules.

Paleontologists have discovered traces of pigment-containing organelles called melanosomes on fossilized feathers before. Trouble is, scientists weren’t sure if the melanosomes, and their associated color, were actually from the preserved creature, or from microbes that collected on the feathers during decomposition and fossilization. More evidence was needed to separate the two possibilities.

That evidence has now arrived in the form of keratin, a fibrous protein that protects certain cells from damage.
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Visit our website ? ?
www.paleontologyworld.com ✔ "

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[Spalea]

Gastornis represent a continuation of the former big velociraptors of the Mesozoic Era near the small mammals, some of them becoming the direct extant horse's ancestors.

" Gastornis was a genus of large flightless birds that lived during the late Paleocene and Eocene epochs of the Cenozoic era. The genus is currently thought to contain three or four distinct species, known from incomplete fossil remains, found in western-central Europe (England, Belgium, France and Germany). More complete specimens are known from a fourth, North American species, which had previously been classified in the distinct genus Diatryma. Many scientists now consider Diatryma to be so similar to the other species of Gastornis that it should also be included in that genus. A fifth species, also previously classified in its own genus, is known from China.


Gastornis is known from a large amount of fossil remains, but the clearest picture of the bird comes from a few nearly complete specimens of the species G. gigantea. These were generally very large birds, with huge beaks and massive skulls superficially similar to the carnivorous South American "terror birds" (phorusrhacids). The largest known species, G. gigantea could grow to the size of the largest moas, and reached about 2 m (6 ft 7 in) in maximum height. " Reply

[Matias]

Molecular exploration of fossil eggshell uncovers hidden lineage of giant extinct bird

Quote:Abstract

The systematics of Madagascar’s extinct elephant birds remains controversial due to large gaps in the fossil record and poor biomolecular preservation of skeletal specimens. Here, a molecular analysis of 1000-year-old fossil eggshells provides the first description of elephant bird phylogeography and offers insight into the ecology and evolution of these flightless giants. Mitochondrial genomes from across Madagascar reveal genetic variation that is correlated with eggshell morphology, stable isotope composition, and geographic distribution. The elephant bird crown is dated to ca. 30 Mya, when Madagascar is estimated to have become less arid as it moved northward. High levels of between-clade genetic variation support reclassifying Mullerornis into a separate family. Low levels of within-clade genetic variation suggest there were only two elephant bird genera existing in southern Madagascar during the Holocene. However, we find an eggshell collection from Madagascar’s far north that represents a unique lineage of Aepyornis. Furthermore, divergence within Aepyornis coincides with the aridification of Madagascar during the early Pleistocene ca. 1.5 Ma, and is consistent with the fragmentation of populations in the highlands driving diversification and the evolution of extreme gigantism over shorts timescales. We advocate for a revision of their taxonomy that integrates palaeogenomic and palaeoecological perspectives.

Introduction

The elephant birds of Madagascar (Aves: Aepyornithidae) were large, flightless ratites that became extinct around a millennium ago. The relatedness of elephant birds to other birds remained a mystery until several genetic studies discovered that they are sister to New Zealand’s kiwi1,2,3, revolutionising our understanding of avian diversification. However, the biodiversity and evolutionary relationships within elephant birds have been uncertain and unstable since they were first described over 150 years ago4, as most species are known only from few incomplete Pleistocene-Holocene post-cranial skeletal remains from south and central Madagascar5,6,7 (Fig. 1a and Supplementary Data 1). About eight species of elephant birds across two genera were generally accepted based on morphological comparison of skeletal fossils4 (Fig. 1c), but a recent morphometric re-evaluation of skeletal material6,7 reclassified elephant birds into four species across three genera (Aepyornis, Mullerornis and a new genus, Vorombe). However, this revision remains questionable: homoplasy in morphological characters that has arisen via convergent evolution means post-cranial skeletal morphology poorly distinguishes species limits within extinct ratite taxa8 as well as the evolutionary relationships between them. Alternatively, the use of ancient DNA (aDNA) has proven to be highly successful in the delineation of extinct bird species boundaries, phylogenetic relationships, and geographic ranges8,9,10,11,12, and corroboration of elephant bird systematics by molecular methods is long overdue. Although the warm, humid environment of Madagascar is suboptimal for the preservation of aDNA in bone13, it has been retrieved from elephant bird eggshell3,14, which is found in abundance while skeletal fossils are less common15. Aided by eggshell micro-morphology, stable isotope geochemistry and palaeoproteomics, here, we detail the first phylogeographic survey of elephant birds using eggshell whole mitochondrial aDNA, in order to revisit elephant bird taxonomy and evolutionary history. As an island with high levels of endemism, Madagascar is a model system for studying the mechanisms underlying evolution and extinction, and the lack of resolution around the life history of the world’s largest birds presents a major gap in our understanding.

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[hibernours]

Terror birds are of course really impressive because of their sizes. Vorombe Titan had a mean mass around 650 kg according to the authors, it is larger than any big cats, extant or extinct. But concerning their height, can someone confirm me scientifically (with some bones or scientific reconstruction)  that some terror birds have reached a height equal or greater than 3 meters high please? If this is confirmed that means that some terror birds could look an african male elephant in the eyes...

Thanks. Reply