jeudi 8 juin 2017

Here goes my Howlibird theory ...

Joel kontinen : Death of a Darwinian Icon: T. Rex Did Not Have Feathers, Fossil Evidence Suggests

Recently, Dr Phil Bell (University of New England, Australia) and colleagues published a paper in the journal Biology Letters, examining skin impressions from a famous T. rex skeleton known as Wyrex.

They found no evidence for feathers.

In contrast, they found “scaly reptilian-like skin.”

Fine article, except certain people like complaining about the wikipedia instead of doing sth.

Some museums and textbooks (as well as Wikipedia, of course) have put feathers on T. rex although there is no fossil evidence that these huge reptiles ever sported them.

I look up wikipedia and see this:

While there is no direct evidence for Tyrannosaurus rex having had feathers, many scientists now consider it likely that T. rex had feathers on at least parts of its body,[33] due to their presence in related species. Mark Norell of the American Museum of Natural History summarized the balance of evidence by stating that: "we have as much evidence that T. rex was feathered, at least during some stage of its life, as we do that australopithecines like Lucy had hair."[34]

The first evidence for feathers in tyrannosauroids came from the small species Dilong paradoxus, found in the Yixian Formation of China, and reported in 2004. As with many other theropods discovered in the Yixian, the fossil skeleton was preserved with a coat of filamentous structures which are commonly recognized as the precursors of feathers.[35] Because all known skin impressions from larger tyrannosauroids known at the time showed evidence of scales, the researchers who studied Dilong speculated that feathers may correlate negatively with body size—that juveniles may have been feathered, then shed the feathers and expressed only scales as the animal became larger and no longer needed insulation to stay warm.[35] However, subsequent discoveries showed that even some large tyrannosauroids had feathers covering much of their bodies, casting doubt on the hypothesis that they were a size-related feature.[36]

While skin impressions from a Tyrannosaurus rex specimen nicknamed "Wyrex" (BHI 6230) discovered in Montana in 2002,[37] as well as some other giant tyrannosauroid specimens, show at least small patches of mosaic scales,[38] others, such as Yutyrannus huali (which was up to 9 meters (30 ft) long and weighed about 1,400 kilograms (3,100 lb)), preserve feathers on various sections of the body, strongly suggesting that its whole body was covered in feathers.[36] It is possible that the extent and nature of feather covering in tyrannosauroids may have changed over time in response to body size, a warmer climate, or other factors.[36]

Research has suggested that large theropods like Tyrannosaurus had teeth covered in lips like modern day lizards, rather than having bare teeth like crocodiles. This is based on the presence of enamel, which may need to remain hydrated, an issue not faced by aquatic species like crocodilians or toothless species like birds, which have lipless mouths and toothless beaks. In modern terrestrial animals with bare teeth, the teeth typically lack some or all of the standard amount of tooth enamel. Because Tyrannosaurus and other toothed theropods had enamel-covered teeth, they would have required some sort of lip-like covering to seal the mouth when closed.[39][40] However, the discovery that Daspletosaurus horneri, a related genus, seemingly did not possess lips and instead seems to have possessed large scales similar to those of crocodiles on its face. Based on comparisons of bone texture of D. horneri with crocodilians, this suggests that Tyrannosaurus and other tyrannosaurids may not have had lips at all and instead had large, flat scales that left no room for lips. The skull of Daspletosaurus horneri also suggests that tyrannosaurids including Tyrannosaurus had integumentary sensory organs similar to crocodilians likely used in touch, temperature readings, prey detection and precise control of jaw movements.[41]

Two hypotheses apart from that of the evolutionists:

  • the dinos with feathers seem to come from China, a country with still a socialist system apart from certain aspects of market economy, and could be frauds;
  • the Dilong paradoxus as well as the Yutyrannus huali, while Chinese, are even so not frauds but could resurrect my Howlibird theory ... they would in that case be another created kind than T Rex and Allosaurus.

Hans Georg Lundahl
Nanterre UL
Thursday in Pentecost Octave

Aucun commentaire:

Enregistrer un commentaire