Thursday, 9 July 2015

Another Intermediate Fossil - Dinosaur Ancestor

Wendiceratops pinhornensis, artists reconstruction
Photo credit: Danielle Dufault

PLOS ONE: Cranial Anatomy of Wendiceratops pinhornensis gen. et sp. nov., a Centrosaurine Ceratopsid (Dinosauria: Ornithischia) from the Oldman Formation (Campanian), Alberta, Canada, and the Evolution of Ceratopsid Nasal Ornamentation | PLOS ONE.

Like I said in a previous blog, these intermediate fossils, which creationists stoically maintain don't exist because they illustrate something they are desperately trying to convince themselves doesn't happen, are so common one could almost dedicate a weekly blog to listing the new ones.

In many ways, this illustrate the difference in approach between intellectually honest science, and the intellectual bankruptcy of creationism. Science sees gaps in the record and looks for the evidence which fills that gap, or more likely finds evidence then works out how it fits in the overall picture; creationists see gaps, force-fits their favourite god in them, ignores the evidence which fills the gap when it's found, declares it proof that evolution doesn't happen and concludes that their evidence-free superstition must be right.

So, here's yet another of those gap-filling pieces of evidence for creationists to ignore and wave aside with their coping mechanism of choice.

A pair of paleontologists have examined over 200 78-79 million year-old fossilised bones from a site in southern Alberta, Canada, consisting of the remains of at least three adult individuals and one juvenile. These show that this new species, Wendiceratops pinhornensis, had a nose horn intermediate between the low, rounded horns of the early horned dinosaurs and the long horns of the Styracosaurus family.

The fossil record of ceratopsid dinosaurs between the occurrence of their proximate sister taxa in the Turonian and the beginning of their well-documented radiation from the late Campanian of North America onwards (approximately 90 and 77 Ma) is poor, with only seven taxa described from this early period in their evolution. We describe a new taxon of a highly adorned basal centrosaurine, Wendiceratops pinhornensis gen. et sp. nov., from the lower part of the Oldman Formation (middle Campanian, approximately 78-79 Ma), Alberta, Canada. Over 200 bones derived from virtually all parts of the skeleton, including multiple well-preserved specimens of the diagnostic parietosquamosal frill, were collected from a medium-density monodominant bonebed, making the new taxon one of the best-represented early ceratopsids. The new taxon is apomorphic in having epiparietals at loci 2 and 3 developed as broad-based, pachyostotic processes that are strongly procurved anterodorsally to overhang the posterior and lateral parietal rami, and an ischium with a broad, rectangular distal terminus. Although the morphology of the nasal is incompletely known, Wendiceratops is inferred to have a large, upright nasal horn located close to the orbits, which represents the oldest occurrence of this feature in Ceratopsia. Given the phylogenetic position of the new taxon within Centrosaurinae, a enlarged nasal horn is hypothesized to have arisen independently at least twice in ceratopsid evolution.*

Although this discovery isn't going to set the world of palaeontology alight and require a root and branch revision of dinosaur evolution, it fills in yet another gap in our knowledge of how this group of horned dinosaurs evolved.

Wendiceratops helps us understand the early evolution of skull ornamentation in an iconic group of dinosaurs characterized by their horned faces... The wide frill of Wendiceratops is ringed by numerous curled horns, the nose had a large, upright horn, and it's likely there were horns over the eyes too. The number of gnarly frill projections and horns makes it one of the most striking horned dinosaurs ever found.

Dr. David Evans, Temerty Chair and Curator of Vertebrate Palaeontology, Royal Ontario Museum, Toronto, Canada.
(Quoted in Science Daily)

Note: no one in paleontology now claims this or that new find confirms evolution. Science moved on from that debate years ago, leaving it to the wackos, loons, science-deniers and right-wing political extremists hiding behind religious fundamentalism.

Evolution is now taken for granted; accepted as proved beyond any shadow of doubt. What they talk about is how this evidence fills in the details and shows how this or that group diversified and from what common ancestor. In other words, science is now about fitting in the pieces of the puzzle to complete the picture. It's no longer about what the pictures shows.

The fact of evolution is no longer doubted any more so than the fact of plate tectonics, the fact of gravity, the fact of a 13.82 billion year-old Universe or the fact that nuclear fission powers the Sun. Science is now about understanding the details and the precise mechanisms of these fundamental facts of existence.

Beyond its odd, hook-like frill, Wendiceratops has a unique horn ornamentation above its nose that shows the intermediate evolutionary development between low, rounded forms of the earliest horned dinosaurs and the large, tall horns of Styracosaurus, and its relatives... The locked horns of two Wendiceratops could have been used in combat between males to gain access to territory or females.

Dr. Michael Ryan, Curator of Vertebrate Paleontology, Cleveland Museum of Natural History
(Quoted in Science Daily)

Creationism is now not a matter of scientific debate about the validity of the evidence but about the psychological processes that underpin creationism, the ignorance which feeds it and the political agenda which depends on keeping people scientifically illiterate and proudly ignorant so they can be easily deceived and manipulated to support measures that no normal human being would normally support.

*Copyright: © 2015 Evans, Ryan. Reproduced under Creative Commons Attribution License CC BY 4.0

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