Nyctosaurus and that crest

Sunday, June 7, 2015

Only five relatively complete Nyctosaurus skulls have been found. Of those, one is juvenile and does not possess a crest (specimen FMNH P 25026), and two are more mature and may show signs of having had a crest but are too badly crushed to say for sure (FHSM 2148 and CM 11422). Two specimens (KJ1 and KJ2) described in 2003, however, preserved an enormous double-pronged crest.

A few scientists had initially hypothesized that this crest, which resembles an enormous antler, may have supported a skin "headsail" used for stability in flight. While there is no fossil evidence for such a sail, studies have shown that a membranous attachment to the bony crest would have imparted aerodynamic advantages. However, in the actual description of the fossils, paleontologist Christopher Bennett argued against the possibility of a membrane or soft tissue extension to the crest. Bennett noted that the edges of each prong were smooth and rounded, and showed no evidence for any soft-tissue attachment points. He also compared Nyctosaurus with large-crested tapejarids, which do preserve soft tissue extensions supported by prongs, and showed that in those species, the attachment points were obvious, with jagged edges where the transition from bone to soft tissue occurred.

Bennett concluded that the crest was most likely used solely for display, citing similar structures in modern animals. The 2009 study by Xing and colleagues testing the aerodynamics of the giant crest with a "headsail" also tested the aerodynamics of the same crest with no sail, and found that it added no significant negative factors, so a crest with no headsail would not have hindered normal flight. It is more likely that the crest acted mainly for display, and that any aerodynamic effects it may have had were secondary. Bennett also argued that the crest was probably not a sexually dimorphic character, as in most crested pterosaurs, including the related Pteranodon, both sexes are crested and it is only the size and shape of the crest that differs. The apparently non-crested Nyctosaurus specimens therefore probably came from sub-adults.

'Hellboy' dinosaur Regaliceratops peterhewsi with exotic facial horns and bony frill, unearthed in Canada

Friday, June 5, 2015

Regaliceratops peterhewsi or 'Hellboy' boasts an exotic set of facial horns and spines around the edge of the bony frill at the back of its skull. (Supplied: Royal Tyrrell Museum of Palaeontology)

Scientists endured a hellish task removing a dinosaur fossil from hard limestone along a Canadian riverbank where it had been entombed for 68 million years, but the diabolic task proved gratifying.
The scientists uncovered one of the most unusual horned dinosaurs ever discovered, a beast boasting an exotic set of facial horns and spines around the edge of the bony frill at the back of its skull.

"This new animal is definitely one of the weirdest horned dinosaurs," said palaeontologist Caleb Brown of the Royal Tyrrell Museum of Palaeontology in Alberta.

"How weird it is really only becomes fully apparent when you compare it to its close relatives, in which case it stands out like a sore thumb."

They officially named it Regaliceratops peterhewsi, meaning "royal horned face" and honouring geologist Peter Hews, who found it.

But they nicknamed it "Hellboy" because its stubby horns above the eyes resembled the comic-book character of the same name and because of the hellish time they had in painstakingly extricating it from what they called "evil hard rock".

"We did have an earlier, politically incorrect name for it, but with great effort we managed to stop ourselves using it after a few months," Royal Tyrrell Museum palaeontologist Donald Henderson said.

Regaliceratops, similar in size to today's largest rhinos, was estimated at 5 metres long, 1.5 metres tall at the hips, weighing about 1.5 tonnes.

"Think of it like a big SUV," Dr Brown said.

 The fossil was found in 2005 along the Oldman River in south-western Alberta, with the tip of the snout sticking out of the cliff. Rather than being squashed flat like many fossils, the skull was in remarkable three-dimensional preservation.

Horned dinosaurs were a formidable group of Cretaceous Period plant-eaters. Regaliceratops lived near the end of the age of dinosaurs.

It possessed a large conical horn over its nose and a pair of small, forward-curving horns over its eyes that were puny compared to its bigger close relative, Triceratops.

Seven bony spines in triangular and pentagonal shapes formed a halo around the edge of its large shield-like frill.

"The complete frill looks like a crown formed around the face of the animal," Dr Brown said.
Nearly the entire skull, but none of the rest of the skeleton, was found.

The research appears in the journal Current Biology.

Itzpapalotl - "Obsidian Butterfly".

Monday, June 1, 2015

"Obsidian Butterfly". Goddess of healing. Aztec and Mexica goddess of the earth and fertility, often seen as the darker aspect of the earth goddess. She is usually depicted as a dragon-like being with fangs and claws, as she was seen to "grasp the sky". Itzpapalotl may be connected with souls of the dead, as the Mexica believed that departed souls often manifested as butterflies.

 n Aztec mythology, Itzpapalotl ("Clawed Butterfly" or "Obsidian Butterfly") was a fearsome skeletal goddess, who ruled over the paradise world of Tamoanchan. She is particularly associated with the moth Rothschildia orizaba from the family Saturniidae.Itzpapalotl is the patron of the day Cozcuauhtli and Trecena 1 House in the Aztec calendar. The Trecena 1 House is one of the five western trecena dates dedicated to the cihuateteo, or women who had died in childbirth. Not only was Itzpapalotl considered one of the cihuateteo herself, but she was also one of the tzitzimime, star demons that threatened to devour people during solar eclipses,as well as their queen.Itzpapalotl is also known as the clouded Apollo. The Goddess got her name because of the broad butterfly wings sprouting from her shoulders with the blades of sharp obsidian knives all the way around the edges; she also has a knife for a tongue.

As the legend goes, Itzpapalotl fell from heaven along with Tzitzimime and several other shapes such as scorpions and toads. Itzpapalotl wore an invisible cloak so that no one could see her. At some times, she was said to have dressed up like a lady of the Mexican Court, caking her face with white powder and lining her cheeks with strips of rubber. Her fingers tapered into the claws of a jaguar, and her toes into eagle's claws.According to the Manuscript of 1558, section VII, Itzpapalotl was one of two divine 2-headed doe-deers (the other one being Chimalman) who temporarily transformed themselves into women in order to seduce men. Itzpapalotl approached the two "cloud serpents named Xiuhnel and Mimich", who transformed themselves into men (so as to diguise themselves when all the others of the Centzonmimixcoa had been slain in the ambush?). To Xiuhnel, Itzpapalotl said ""Drink, Xiuhnel." Xiuhnel drank the blood (menstrual?) and then immediately lay down with her. Suddenly she ... devoured him, tore open his breast. ... Then Mimich ... ran and ... descended into a thorny barrel cactus, fell into it, and the woman fell down after him."

Dinosaurs Were Warm-Blooded, Scientist Suggests

Torvosaurus gurneyi. Image credit: © Sergey Krasovskiy.

Dinosaurs were endothermic (warm-blooded) like mammals, says paleontologist Dr Michael D’Emic of Stony Brook University.

In a 2014 study, a team of scientists led by Dr John Grady of the University of New Mexico suggested that non-avian dinosaur metabolism was neither endothermic nor ectothermic (cold-blooded) but an intermediate physiology termed ‘mesothermic.’

Based on his knowledge of how dinosaurs grew, Dr D’Emic re-analyzed that study, which led him to the strikingly different conclusion that dinosaurs were more like mammals than reptiles in their growth and metabolism.

“The study that I re-analyzed was remarkable for its breadth – the authors compiled an unprecedented dataset on growth and metabolism from studies of hundreds of living animals. Upon re-analysis, it was apparent that dinosaurs weren’t just somewhat like living mammals in their physiology – they fit right within our understanding of what it means to be a ‘warm-blooded’ mammal,” Dr D’Emic said.

He re-analyzed the 2014 study from two aspects. First, the study had scaled yearly growth rates to daily ones in order to standardize comparisons.

“This is problematic, because many animals do not grow continuously throughout the year, generally slowing or pausing growth during colder, drier, or otherwise more stressful seasons,” said Dr D’Emic, author on the paper published in the journal Science.

“Therefore, the previous study underestimated dinosaur growth rates by failing to account for their uneven growth. Like most animals, dinosaurs slowed or paused their growth annually, as shown by rings in their bones analogous to tree rings.”

“The growth rates were especially underestimated for larger animals and animals that live in very stressful or seasonal environments – both of which characterize dinosaurs.”

The second aspect of the re-analysis with the original study takes into account that dinosaurs should be statistically analyzed within the same group as living birds, which are also warm-blooded, because birds are descendants of Mesozoic dinosaurs.

“Separating what we commonly think of as ‘dinosaurs’ from birds in a statistical analysis is generally inappropriate, because birds are dinosaurs – they’re just the dinosaurs that haven’t gone extinct.”
“Re-analyzing the data with birds as dinosaurs lends more support that dinosaurs were warm-blooded, not occupants of a special, intermediate metabolic category.”
M. D. D’Emic. 2015. Comment on “Evidence for mesothermy in dinosaurs.” Science, vol. 348, no. 6238, p. 982; doi: 10.1126/science.1260061