Crazyhen Posted November 30, 2017 Share Posted November 30, 2017 Any idea what species of horseshoe crab is that (or is it genuine)? Is horseshoe crab fossil very rare? The specimen was said to be collected from Hebei, China. Link to post Share on other sites
Tidgy's Dad Posted November 30, 2017 Share Posted November 30, 2017 Whatever this is it looks genuine to me, but I don't think it's a horseshoe crab. I've never seen one with a bifurcated telson. I think it's some other type of arthropod. 4 Link to post Share on other sites
LordTrilobite Posted November 30, 2017 Share Posted November 30, 2017 Looks a bit like a Triops to me. So yeah, not a Horseshoe crab. 7 Link to post Share on other sites
Fossildude19 Posted November 30, 2017 Share Posted November 30, 2017 I agree - it is a Notostracan. Also known as a "tadpole shrimp" or "shield shrimp". 6 Link to post Share on other sites
-Andy- Posted November 30, 2017 Share Posted November 30, 2017 It's a Triops. The fossil ones from China I've seen are always Weichangiops sp. 3 Link to post Share on other sites
oilshale Posted November 30, 2017 Share Posted November 30, 2017 There are several places in China where you can find horseshoe crabs - Yunnanolimulus luopingensis Zhang, Hu, Zhou, Lu & Bai, 2009 from the Triassic of Yunnan seems to be the most common.l Weichangopsis from the Cretaceous of Liaoning has two soft tail spines - Yunnanolimulus got only one hard spine. 7 Link to post Share on other sites
doushantuo Posted November 30, 2017 Share Posted November 30, 2017 Sizewise,maybe a (nebalimorph)leptostracan? Spinicaudatan? Edit:notostracans in the 5-6 cm size range do exist,so .... I'll let it stand,because small leptostracans CAN look a bit like branchiopods The Yixian notostracan Chenops Link to post Share on other sites
oilshale Posted December 1, 2017 Share Posted December 1, 2017 I am very sure, this is a Weichangiops from the Cretaceous. I've got 2 or 3 of them. At least two species are described: W. rotundus and W. triangularis. 2 Link to post Share on other sites
Ludwigia Posted December 1, 2017 Share Posted December 1, 2017 20 hours ago, Crazyhen said: Any idea what species of horseshoe crab is that (or is it genuine)? Is horseshoe crab fossil very rare? The specimen was said to be collected from Hebei, China. There appears to be a second, smaller object in the second photo. Is it possible that this is Euproops? I know it doesn't fit the surmised stratigraphy, but.... Link to post Share on other sites
oilshale Posted December 1, 2017 Share Posted December 1, 2017 You are right - there is a smaller object. Don't know what it is, but Euproops or other Limulidae are very unlikely to occur in the Yixian formation. The deposits consist of fresh water sediments, they are not marine deposits. Link to post Share on other sites
abyssunder Posted December 1, 2017 Share Posted December 1, 2017 " Upper Jurassic fresh-water Triopsids recently discovered from Weichang, Hebei consist of one new subfamily (Weichangiopsinae subf. nov.), two new genera (Weichangiops gen. nov. and Brachygastriops gen. nov.) and three new species (Weichangiops triangularis gen. et sp. nov., W. rotundus gen. et sp. nov. and Brachygastriops xinboensis gen. et sp. nov.) Family Triopsidae Martalent,1935 is emended to include species having a single eye, broadly rounded carapace, denticulate posterior marginal notch and entire abdomen without being differentiated into anterior and posterior portions. It may be divided into two subfamilies: subf. Triopsinae Martalent 1935 and the newly erected subf. Weichangiopsinae based on having a single eye, carapace broader than long, posterior marginal notch of carapace denticulated and abdomen not differentiated into anterior and posterior portions. Generic characters include (1) the ratio of abdominal length to carapace length, (2) number of thoracic and abdominal somites, (3) appendages either foliate or needle-shaped and (4) oral apparatus when preserved.The evolution of the group is also discussed. " I. 1-2 Weichangiops triangularis II. 1-3 Weichangiops triangularis III. 1-3 Weichangiops rotundus, 4 Brachygastriops xinboensis excerpts from a basic reference: Yang Zun-yi, Hong You-chong. 1980. Discovery of fresh-water Triopsids from the Upper Jurassic Dabeigou formation of Weichang, Hebei, China and its bearing on the classification of the family Triopsidae Martalent. Acta Palaeontologica Sinica,Vol.19 (2): 91-99 4 Link to post Share on other sites
abyssunder Posted December 1, 2017 Share Posted December 1, 2017 " In the present paper the two species Triops hanshanensis Chen sp. nov. and T. bashuensis Duan sp. nov. from the Middle Jurassic of South China are described, and the two genera Weichangiops and Brachygastriops have been revised to Lepidurus. In addition, geographical distributions of the Mesozoic and living forms of Notostraca are also briefly discussed. " excerpts from: Chen Pei-ji. 1985. Jurassic Triops from South China - With a discussion on the distribution of Notostraca. Acta Palaeontologica Sinica Vol. 24(3): 285-292 3 Link to post Share on other sites
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now