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Hello all, I have a question wrt age of the eggs, and to know which genus and oogenus this might be. Before, here, I had posted a lot of photos and a video but somehow they are mostly gone, so I will repost the video. What I have from the seller Hadrosauridae family, possibly Saurolophus genus Possibly Dendroolithus oogenus 80 mio. year old, Cenomanian, Late Cretaceous Egg size 10.5 to 12cm (4 to 4.5"), about 8-9kg (18lbs) Xixia Basin, Henan province, China Now come the contradictions of the above given data Hadrosauridae: 86–66 Ma (mio. years ago) --> Santonian-Maastrichtian (2) Saurolophus: 70–66 Ma --> Maastrichtian (3) "80 mio. year old" --> Campanian "Cenomanian" <-- 100.5-93.9 Ma Dendroolithus: 99–66 Ma --> complete Late Cretaceous (1,4) Most websites state those kind of eggs are from 80-70 or 84-71 Ma --> Santonian-Maastrichtian (1,5,6,7) On an online auction site, I found 70-65 Ma --> Maastrichtian (8) ScienceDirect states Dendroolithus oogenus from Xixia Basin are 96-83 Ma --> Cenomanian-Santonian (9) Could potentially be from Gaogou Formation, Majiacun Formation, or Sigou Formation (10,11,12) (https://en.wikipedia.org/wiki/Late_Cretaceous) So, all this does not fit together really well, does it? As Hadrosauridae lived during Santonian-Maastrichtian, 86–66 Ma, everything older should be ruled out, correct? Thus, if ScienceDirect is right, we should be within 86-83 Ma, which is Santonian. If so, most websites (5,6,7,8 & of my seller) are wrong, plus, it ain't be Saurolophus. ==} Can anyone explain this? References https://digsfossils.com/fossils/china_eggs.html https://en.wikipedia.org/wiki/Hadrosauridae https://en.wikipedia.org/wiki/Saurolophus https://en.wikipedia.org/wiki/Dendroolithus http://www.online fossil retailer.com/Stonerelic/vertebrates/EH015/EH015.htm https://www.jurassic-dreams.com/products/30116-huge-and-nicely-preserved-hadrosaurus-egg-in-matrix-kaoguo-fm-cretaceous-china-fossil-for-sale https://www.buriedtreasurefossils.com/hadrosaur-egg.html https://www.online auction site.com/zh-Hant/l/28862073-nest-of-10-hadrosaur-eggs-plus-3-imprints-all-original-no-restoration-69-x-44-cm https://www.sciencedirect.com/science/article/pii/S1002007109002949?via%3Dihub https://en.wikipedia.org/wiki/Gaogou_Formation https://en.wikipedia.org/wiki/Majiacun_Formation https://en.wikipedia.org/wiki/Sigou_Formation Update 1: video doesn't play any more in the browser. Will upload photos and fix the video.

Howdy all, I've recently heard that hadrosaurs originated in Appalachia, and it was essentially their "ancestral homeland." Is this true?

You do not see a lot described from Japan so its nice to see this one. . Discovered in the marine Maastrichtian deposits of the Kitaama Formation. Yamatosaurus izanagii https://www.nature.com/articles/s41598-021-87719-5#disqus_thread

The first Hadrosauridae from the Maastrichtian of Morocco is described in this paper. Pretty cool, its a lambeosaurine called Ajnabia odysseus. From Ouled Abdoun Basin. Its also the first named hadrosaur from Africa. Hopefully will see some teeth on the market. Sorry its Paywalled https://www.sciencedirect.com/science/article/abs/pii/S0195667120303657 See below for additional images

Although identification of Hadrosaurid teeth in North America is very difficult or impossible some older publications by John Horner give us some information to help us with a few. The information goes back a bit so there might be some new understanding but will share what is published. If anyone has publications that can add to the dentary information of teeth from North America please feel free to post it. Horner notes that on dentary teeth all Saurolophinae teeth have diamond-shaped crown whereas Lambeosaurinae teeth are more elongate see figure 13.4. So one may not be able to assign it to a specific genus but a Subfamily may be possible. Maxillary teeth can be different but not discussed.. Saurolophinae include: Edmontosaurus, Kritosaurus, Gryposaurus, Brachylophosaurus, Maiasaura, Brachylophoslaurus Lambeosaurinae include: Lambeosaurus, Parasaurolophus, Corythosaurus, Hypacrosaurus I would suggest that only complete teeth with fairly good preservation be used in any attempt to identify these teeth. Hell Creek & Lance Formation A publication on Edmontosaurus diversity in North America by N. Campione and D. Evans 2011 concluded that all there is only one species of hadrosaur in these faunas so all teeth found can be assigned to Edmontosaurus annectens. Judith River Formation Horner identifies dentary teeth with small denticles as Gryptosaurus (However not sure its been described from JRF so I would question this assignment) Two Medicine Formation Horner identifies dentary teeth with big denticles as Gryptosaurus latidens Horner identifies dentary teeth with very small denticles as Prosaurolophus maximus Hypacrosaurus stebingeri - The figure below shows variations with several species of dentary teeth Book: John Horner: Evidence of diphyletic origination of the Hadrosaruian in Dinosaur Systematics Approaches & Perspective Currie & Carpenter Chapter 13 Book: Dinosaurs under the Big Sky by Jack Horner 2001

Hey everyone, I recently came across these two teeth online. They're both pretty worn down and might no longer possess the features necessary for a more detailed ID, but I'd appreciate your help in confirming that these are actually Hadrosaurid teeth. [images attached are the seller's] Tooth 1 comes from the Judith River Formation of Montana; measuring roughly 9mm [not specified in which direction; I assume depth].  Tooth 2 comes from parts of the Aguja Formation in Western Texas; measuring approximately 13x11mm [not specified along which sides]. Thank you for your help!