New plesiosaur, Argentinonectes calafatensis, is described from a rather complete skeleton from Upper Cretaceous Patagonia. It helps shed light on the tail anatomy for these plesiosaurs.
Argentinonectes calafatensis (Ar-Gen-Teen-Oh-Neck-Tease | Cah-Lah-Fah-Ten-Sis) "Argentino Lake Swimmer from Calafate"
Paper here:
We describe a partial skeleton referred to a new elasmosaurid taxon, Argentinonectes calafatensis gen. et sp. nov., from the Maastrichtian C
Looking at them, they are spectacularly turtle-like, but they’re actually a Sauropterygian! This means they’re a closer relative to Plesiosaurs than to Testudine Turtles!
For a true turtle, look for Archelon, the mega turtle of the Cretaceous!
2: This pathetic little beast is a baby atopodentatus, which actually couldn’t bend their elbows, and after that I made this
To continu the info, atopodentatus was a weird basal sauropterygian that had a flat mouth that was originally reconstructed as a strange zipper thingy which is because the holotype was squeeshed sideways when fossiling. We think it might have used its mouth to scrape algae of rocks like a marine iguana or to filter shit out of mud like morturneria we drew right before
Referred Species: N. mirabilis, N. cristatus, N. cymatosauroides, N. edingerae, N. giganteus, N. haasi, N. jagisteus, N. marchicus, N. mirabilis, N. tchernovi, N. yangjuanensis, N. zhangi
Time and Place: From 242 million years ago until 208 million years ago, from the Ladinian of the Middle Triassic through the earliest Rhaetian of the Late Triassic
Nothosaurus is known from all over Eurasia and North Africa, to the point that it’s pointless to list all the locations. Just assume that if it’s the Mid or Late Triassic of the Tethys Sea, Nothosaurus is there.
Physical Description: Nothosaurus is an iconic Triassic marine reptile - to the point that we had to include it, or else we would have violated some sort of rule of paleontology. Nothosaurus was about 4 meters long on average, but could reach up to 7 meters in length. It had a long, streamlined body, with a long neck and a long tail. Its head was narrow and filled with long and pointed teeth which interlocked together when the mouth closed, forming a tight trap. Its forelimbs were longer than its hind limbs, and all of its hands and feet had webbing between the long toes. In a lot of ways, it looked extremely similar to later marine reptiles to which it was closely related, like the Plesiosaurs and Pliosaurs, just with hands instead of proper flippers - however, current evidence indicates that the Plesiosaurs and Pliosaurs evolved from an ancestor of both groups, and Nothosaurus is just a Triassic offshoot. It had capabilities for diving in the water, though it also was still adapted for life on the shore.
Diet: Nothosaurus primarily ate fish and other marine animals, including other marine reptiles.
Behavior: Nothosaurus was semi-aquatic, spending a lot of its time both in the ocean and on land. On the beaches and shores it would rest and sleep, and then turn to the ocean for most of its everyday life. Diving for food would have been most of its daily activities, going after juvenile reptiles and large fish in the water and diving in order to reach it. It probably would have paddled with its webbed feet, and undulated its body to some extent to help propel forward. It may have been at least somewhat social, living in groups and colonizing the shores together before going for group dives for food. Interestingly enough, Nothosaurus was basically like a reptilian seal, coming up to shore to rest and sit with its relatives. Whether or not they would have given birth to live young is uncertain; while their close relatives, the Plesiosaurs, did; they retained enough land adaptations to allow them to lay eggs on the shore. More research as to their physiology is needed in order to determine that aspect of their life history. Trackways have been attributed to Nothosaurus, which may show that they rowed their paddles on the sea bed to shake up small animals trapped underneath; this would have allowed Nothosaurus to capture the invertebrates between its long teeth and hold onto them so they could not escape.
Ecosystem: Nothosaurus lived throughout the early Tethys sea, and was a common feature in many communities throughout this growing body of water during the Middle and Late Triassic. It would have stuck to the coasts for the most part, but still ventured out into deep and open water. As such, it’s rather difficult to list all the different animals it lived alongside - it’s found in Bulgaria, China, France, Germany, Hungary, Israel, Italy, Jordan, the Netherlands, Poland, Saudi Arabia, Spain, and Switzerland. So just, assume that a marine creature from the Tethys during this time lived with Nothosaurus rather than not.
Other: Nothosaurus has been treated as, unfortunately, a wastebasket taxon - it was discovered early enough in the history of paleontology as a science that many similar animals were just dumped into this name without any specific studies done. So, determining the factual relationships from this mess is still being worked out; in fact, it seems that this genus is paraphyletic, with many close relatives of Nothosaurus being more closely related to some species than to others. So that’s fun!
Species Differences: The varying species of Nothosaurus tend to differ based on where and when they lived, rather than any particularly notable differences. There are some differences in size and limb proportions as well, but in general the differing species of Nothosaurus would have had very similar ecological roles.
~ By Meig Dickson
Sources Under the Cut
Albers, P. C. H., and O. Rieppel. 2003. A new species of the sauropterygian genus Nothosaurus from the Lower Muschelkalk of Winterswijk, The Netherlands. Journal of Paleontology 77(4):738-744.
Albers, P. C. H. 2005. A new specimen of Nothosaurus marchicus with features that relate the taxon to Nothosaurus winterswijkensis. Vertebrate Palaeontology 3 (1): 1- 7.
Brotzen, F. 1956. Stratigraphical studies on the Triassic vertebrate fossils from Wadi Raman, Israel. Arkiv foer Mineralogi och Geologi 2(9):191-217.
Chrzastek, A. 2008. Vertebrate remains from the Lower Muschelkalk of Raciborowice Górne (North-Sudetic Basin, SW Poland). Geological Quarterly 52:225-238.
Diedrich, C. 2009. The vertebrates of the Anisian/Ladinian boundary (Middle Triassic) from Bissendorf (NW Germany) and their contribution to the anatomy, palaeoecology, and palaeobiogeography of the Germanic Basin reptiles. Palaeogeography, Palaeoclimatology, Palaeoecology 273 (1): 1 - 16.
d'Orbigny, A. 1849. Cours Élémentaire de Paléontologie et de Géologie Stratigraphiques [Elementary Course in Paleontology and Stratigraphic Geology] 1:1-299.
Haas, G 1980. Ein Nothosaurier-Schädel aus dem Muschelkalk des Wadi Ramon (Negev, Israel). Annalen des Naturhistorischen Museums in Wien 83:119-125.
Haines, Tim, and Paul Chambers. The Complete Guide to Prehistoric Life. Pg. 64. Canada: Firefly Books Ltd., 2006
Hinz, J. K., A. T. Matzke, and H.-U. Pfretzschner. 2019. A new nothosaur (Sauropterygia) from the Ladinian of Vellberg-Eschenau, southern Germany. Journal of Vertebrate Paleontology.
Jiang, W.; Maisch, M. W.; Hao, W.; Sun, Y.; Sun, Z. 2006. Nothosaurus yangjuanensis n. sp. (Reptilia, Sauropterygia, Nothosauridae) from the middle Anisian (Middle Triassic) of Guizhou, southwestern China. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte. 5: 257–276.
Jiang, D.-Y., L. Schmitz, R. Motani, W.-C. Hao, and Y.-L. Sun. 2007. The mixosaurid ichthyosaur Phalarodon cf. P. fraasi from the Middle Triassic of Guizhou Province, China. Journal of Paleontology 81(3):602-605.
Klein, N. and P. C. H. Albers. 2009. A new species of the sauropsid reptile Nothosaurus from the Lower Muschelkalk of the western Germanic Basin, Winterswijk, The Netherlands. Acta Palaeontologica Polonica 54(4):589-598.
Lin, W.-B.; Jiang, D.-Y.; Rieppel, O.; Motani, R.; Ji, C.; Tintori, A.; Sun, Z.-Y.; Zhou, Min 2017. A new specimen of Lariosaurus xingyiensis (Reptilia, Sauropterygia) from the Ladinian (Middle Triassic) Zhuganpo Member, Falang Formation, Guizhou, China. Journal of Vertebrate Paleontology 37 (2): e1278703.
Liu, J. 2014. A gigantic nothosaur (Reptilia: Sauropterygia) from the Middle Triassic of SW China and its implications for the Triassic biotic recovery. Scientific Reports 4: 7142.
Lu, H., D.-Y. Jiang, R. Motani, P.-G. Ni, Z.-Y. Sun, A. Tintori, S.-Z. Xiao, M. Zhou, C. Ji and W.-F. Fu. 2018. Middle Triassic Xingyi Fauna: Showing turnover of marine reptiles from coastal to oceanic environments. Palaeoworld 27(1):107-116.
Münster, G. G. 1834. Preliminary news about some new reptiles in the shell limestone of Baiern. New Yearbook for Mineralogy, Geognosy, Geology and Petriology 1834 : 521-527.
Palmer, D. ed. 1999. The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 72.
Rieppel, O., and J.-M. Mazin. 1997. Speciation along rifting continental margins: a new nothosaur from the Negev (Israel). Comptes rendus de l'Académie des Sciences Série IIA, Sciences de la Terre et des planètes 326:991-997.
Rieppel, O. 2001. A new species of Nothosaurus (Reptilia: Sauropterygia) from the Upper Muschelkalk (Lower Ladinian) of southwestern Germany. Palaeontographica Abteilung A 263:137-161.
Sepkoski, J. J. 2002. A compendium of fossil marine animal genera. Bulletins of American Paleontology 363:1-560.
Plesiosaurus! Somehow this is the only plesiosaur I have in my shop, that will be updating soon! I have sketches for Nyxosaurus, Elasmosaurus, and Lindwurmia-- any you think I should add?
I also might redo this design, I've updated it since but I didn't draw the head correctly :(
Get this sticker here!
