Troodon Posted March 24, 2017 Share Posted March 24, 2017 The Hell Creek/Lance Formations have been very slow giving up their dinosaur secrets. Very few articulated skeletons have been found other than the king T rex. A couple of recent finds may increase the number of Caenagnathids in these fauna's. Caenagnathids are part of a group of bird like dinosaurs that are known by their easily identifiable hand claws. Currently only Anzu wyliei is described and accepted from these formations and is known from two partially articulated specimens and is the largest Caenagnathid in the fossil record. In 2013 a new species was was described from the Aguja Formation of Texas: Leptorhynchos gaddisi. Bones recovered from the Hell Creek of eastern Montana have similarities to this species and have been described as Leptorhynchos elegans but there still some uncertainty over that find. The current North American view of Caenagnathids is shown in this paper http://www.sciencedirect.com/science/article/pii/S0195667114001700 In August of 2016 a presentation was made at CSVP by David Evans et al. on a new large bodied Caenagnathid that was similiar to Anzu wyliei. The finds were fragmentary but could not be assigned to A. wyliei with expectations it was a new species . Artist (Paleop) rendition of these dinosaurs. Impact on collectors.... Hand and foot claws are typically what you see sold as Anzu wyliei. The hand claws I have in my collection are not all identical and now could be explained by these different species. In fact I have a jumbo toe bone that just did not fit A. wyliei but may be perfect for this larger foot specimen. Also specimens sold as juvenile A. wyliei may just be something else. No hand or foot claws claws have been discovered in the Hell Creek with these new finds so it's uncertain if they have a different morphology. Bottom line to collectors and a common thread is that identification of isolated bones to a species level is very difficult and problematic. We are still in the discovery phase in the Hell Creek/Lance Formations and have lots to learn. One prominent paleontologist suggested around 5 Caenagnathids in these fauna's. Purchase and collect specimens because they are cool, unique and special but don't get hung up in the name. The hand claws are very cool. From my collection and collected in 2014 Link to comment Share on other sites More sharing options...
doushantuo Posted March 24, 2017 Share Posted March 24, 2017 FUN! Link to comment Share on other sites More sharing options...
doushantuo Posted March 24, 2017 Share Posted March 24, 2017 jawsymphysisdentariesChina Link to comment Share on other sites More sharing options...
FossilDAWG Posted March 24, 2017 Share Posted March 24, 2017 Very informative post. Thanks! I wonder if the artist who did the reconstructions was having a bit of fun making them making them look so much like chickens. "Hell chicken" indeed! I always wonder about those land area/sea reconstructions such as the ones used in the locality/distribution maps. I have collected Late Campanian marine fossils (ammonites, crabs, etc) from the east coast of Vancouver Island, which was supposedly in the middle of a land mass according the left hand map. Also (assuming the grey area is land and the white is ocean) northern Vancouver Island and a lot of northern British Columbia was supposedly marine in the Maastrichtian, but there are no marine Maastrichtian rocks anywhere in that area. There seems to be a great degree of "license", or perhaps outright imagination, in those maps. Don Link to comment Share on other sites More sharing options...
Troodon Posted March 24, 2017 Author Share Posted March 24, 2017 25 minutes ago, FossilDAWG said: Very informative post. Thanks! I wonder if the artist who did the reconstructions was having a bit of fun making them making them look so much like chickens. "Hell chicken" indeed! Don Thanks Don Well you're not far from the truth. The nickname of Anzu wyliei is "chicken from hell" so that's where the artist probably got his inspiration. I think artist are very creative individuals and like to embellish everything. Link to comment Share on other sites More sharing options...
Susan from PA Posted March 24, 2017 Share Posted March 24, 2017 Awesome post, Troodon! Very interesting indeed! Hell Creek is a very stingy Formation, and doesn't like to give up its secrets easily. There is so much yet to be discovered and learned, which makes this hobby exciting. It's also the reason I put all of my fossil indentification cards in pencil. . Link to comment Share on other sites More sharing options...
Troodon Posted March 24, 2017 Author Share Posted March 24, 2017 15 minutes ago, Susan from PA said: It's also the reason I put all of my fossil indentification cards in pencil. . Thanks Susan JUST make sure you have lots of them Link to comment Share on other sites More sharing options...
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