Sunday, April 13, 2014

Jawless armored fish from the Ordovician: the Arandaspids

Jawless armored fish from the Ordovician: the Arandaspids

My reconstruction of Sacabambaspis janvieri.
The fossil record of fish during the Ordovician, the period that follows the Cambrian around 485 MYA, is quite poor and consists of just a little more than a handful of named taxa. One of the prominent groups of that time appears to be the Arandaspids. They were jawless (a condition shared by all other vertebrates in these ancient seas) and characterized by a head covered with a bony shield consisting of a flattish dorsal plate, a rounded ventral plate, and a few other smaller plates. Arandaspids were quite primitive looking with two eyes and two nostrils in the front, a series of branchial openings, each protected by bony platelets, on the side between the dorsal and ventral plates. The back portion of the animal was protected by strips of bony armor arranged in chevrons. They had a caudal fin, but no paired fin, making them not particularly good swimmers. They probably lived on the seafloor feeding on microorganisms or organic detritus sucked in through their jawless mouth. All Arandaspids were marine.

My reconstruction of Arandaspis prionotolepis.
The type species of the group is Arandaspis prionotolepis from the shallow marine deposits of the Stairway Sandstone in the Northern Territory, Australia, and dating from the Earliest Middle Ordovician. This 10-15 cm long fish, originally described in 1977 (Ritchie & Gilbert-Tomlinson, 1977) is known from several specimens, some quite complete. The other relatively well known species is Sacabambaspis janvieri from the Anazaldo Formation of Bolivia, which was discovered among a fauna composed almost exclusively of lingulid brachiopods, an indication that it lived near the littoral in a well oxygenated area. Initially described from three bone fragments in 1986 (Gagnier & Blieck, 1986), new fossils were later found including a complete articulated specimen (Pradel et al., 2007) that preserved the uniquely shaped hypocercal tail (the end tip of the vertebral column bends downward supporting the bottom lobe of the tail). The Anzaldo Formation was originally believed to be of Early Upper Ordovician age, but it may actually have been older making Sacabambaspis quite contemporary with Arandaspis (Gagnier et al., 1996). Sacabambaspis was a bit larger than its Australian counterpart, reaching a length of 25 cm.

Articulated fossil specimen of Sacabambaspis janvieri. From User:Ghedoghedo, Wikipedia commons
Another fish, Andinaspis suarezorum from the Capinota Formation of Bolivia, known from a single poorly preserved fragment, was once thought to be Early Middle Ordovician and classified as a possible Arandaspid, but there are now doubts on its actual age, which turned out to be in all probability Devonian (Gagnier et al., 1996). Also from Bolivia, but from the Pircancha Formation of Early Ordovician age, comes what seems to a be ventral shield of a possible large Arandaspid christened Pircanchaspis rinconensis (Erdtmann et al., 2000) This is the earliest record of a fish from South America. From Australia, Porophoraspis crenulata from the same location and age than Arandaspis was described in the same paper than the latter,  but is much less known as only a single external mould of a small plate has been recovered. This one is also a possible Arandaspid.

Arandaspids belong to one of the two major groups of armored jawless fish that would dominate the first part of the Paleozoic era: the Heterostraci or Heterostracomorphs, the other group being the Cephalaspids. Arandaspids apparently did not last longer than the Ordovician, being replaced by far more efficient forms in the Silurian.

References:

Erdtmann, B., Weber, B., Schultze, H.-P., & Egenhoff, S. (2000). A possible agnathan plate from the Lower Arenig (Lower Ordovician) of South Bolivia. Journal of Vertebrate Paleontology, 20(2), 394–399.

Gagnier, P., Blieck, A., & G., R. S. (1986). First Ordovician vertebrate from South America. Geobios, 19(5), 629–634.

Gagnier, P., Blieck, A., Emig, C., Sempere, T., Vachard, D., & Vanguestaine, M. (1996). New paleontological and geological data on the Ordovician and Silurian of Bolivia. Journal of South American Earth Sciences, 9(5/6), 329–347.

Pradel, A., Sansom, I. J., Gagnier, P.-Y., Cespedes, R., & Janvier, P. (2007). The tail of the Ordovician fish Sacabambaspis. Biology Letters, 3(1), 73–76.

Ritchie, A., & Gilbert-Tomlinson, J. (1977). First Ordovician vertebrates from the southern hemisphere. Alcheringa, 1(4), 351–368.

Sunday, April 6, 2014

Early vertebrates: the Myllokunmingiidae

My reconstruction of the early vertebrate Haikouichthys ercaicunensis, based on Zhang & Hou, 2004.
Early vertebrates: the Myllokunmingiidae

Molecular data of extant fauna places the divergence of vertebrates (animals with a backbone, including mammals, birds, reptiles, amphibians and fish) from their closest relatives, the cephalochordates (Amphioxus) as far back as 751 MYA (Hedges, 2001) during the Cryogenian period of the proterozoic. This is well before the Ediacaran biota (575 MYA) and the so-called Cambrian explosion (542 MYA). However, it was recently shown that the molecular clock ran some five times faster during the Cambrian than during any other period that followed (Lee, 2013). A more conservative and reasonable estimate would therefore make the vertebrates appeared at the very end of the Proterozoic or during the Lower Cambrian along many other phyla. What does the fossil record says? For a while, the earliest undisputed vertebrate fossil remains consisted of some isolated dermal bones dating from the Early Ordovician (480 MYA) of central Australia and belonging to a group of jawless fish called Arandaspida. This situation changed quite a bit in 1999 with the discovery and description of two fossils from the famous Chengjiang biota of the Maotianshan Shale in the Yunnan Province of China, dating from the middle of the Lower Cambrian (525-520 MYA). Two species were erected, Myllokunmingia fengjiaoa Shu et al., 1999 and Haikouichthys ercaicunensis Luo et al., 1999, regrouped into the family Myllokunmingiidae. A third species, Zhongjianichthys rostratus Shu, 2003 has been added to the list four years later.

Haikouichthys (“Haikou fish”) is by far the best known of the three. Originally based on a single incomplete specimen, it is today known from more than 500 specimens from the same fossil locality near Haikou, in the Kunming prefecture of Yunnan. Measuring about 2.5 cm in length, Haikouichthys has an elongated fish-like body with a single dorsal, ventral and caudal fin, as shown from a remarkably well-preserved specimen (Zhang & Hou, 2004). It is not easy to interpret faint impressions within the fossils but structures and internal organs such as vertebrae, paired eyes, guts, heart, and possibly a nostril, an olfactory organ have been identified. Haikouichthys had a number of gill pouches and series of W shape myomeres (muscle blocks that are typical in fish).  The presence of a mouth can only be inferred as it is not clearly visible in the fossils. Haikouichthys was certainly an active swimmer but probably not a good one because of the lack of paired fins. Haikouichthys and the other Myllokunmingiids appear to be the most primitive agnathans (jawless fish). Phylogenetic analysis indicates that this is a stem vertebrate more primitive than lampreys and any other known jawless fish.

Myllokunmingia (“Kunming fish”) is known from a single 2.8 cm long specimen. It is usually seen as being a bit larger and bulkier than Haikouichthys. However, a new fossil (Hou et al., 2002) showing a combination of characters found in Haikouichthys and Myllokunmingia, may indicate that the two constitute in fact a single animal (in that case, the name Myllokunmingia would have precedence over Haikouichthys) and any observed differences may rather reflect preservation bias. This view is however not universally recognized. Zhongjianichthys is a problematic animal that has been classified as a Myllokunmingiid, but not enough is known about it for this attribution to be certain. Another Maotianshan Shale animal, Haikouella lanceolata Chen, Huang & Li, 1999, known from more than 300 specimens, is often considered as another possible stem vertebrate. However it looks so similar to the contemporaneous Yunnanozoon lividum, a possible hemichordate or stem chordate, that this attribution is somewhat unlikely. Most specimen of Haikouella measured 2.5 to 3 cm in length with some individuals reaching 4 cm.

Reference:

Chen, J., Huang, D., & Li, C. (1999). An early Cambrian craniate-like chordate. Nature, 402(December), 518–522.

Hedges, S. (2001). Molecular evidence for the early history of living vertebrates. In Major Events in Early Vertebrate Evolution, 119–134.

Lee, M. S. Y., Soubrier, J., & Edgecombe, G. D. (2013). Rates of phenotypic and genomic evolution during the Cambrian explosion. Current Biology, 23(19), 1889–95.

Shu, D., Luo, H., Morris, S., Zhang, X., & Hu, S. (1999). Lower Cambrian vertebrates from south China. Nature, 402(November), 42–46.

Shu, D., Morris, S., Han, J., & Zhang, Z. (2003). Head and backbone of the Early Cambrian vertebrate Haikouichthys. Nature, 421(January), 526–529.

Xian-guang, H., Aldridge, R. J., Siveter, D. J., Siveter, D. J., & Xiang-hong, F. (2002). New evidence on the anatomy and phylogeny of the earliest vertebrates. Proceedings. Biological Sciences / The Royal Society, 269(1503), 1865–9.

Zhang, X.-G., & Hou, X.-G. (2004). Evidence for a single median fin-fold and tail in the Lower Cambrian vertebrate, Haikouichthys ercaicunensis. Journal of Evolutionary Biology, 17(5), 1162–6.

Tuesday, April 1, 2014

Old views on dull-witted semi-aquatic dinosaurs correct after all…


A new study suggests dinosaurs were aquatic... too heavy to move on land.
For more than half a century, dinosaurs were depicted as slow-moving creatures living in swampy environments. Giants such as the 35 tons Brachiosaurus were deemed too heavy on land to be able to support their own weight and the prominent view for most of the 20th century was that they were amphibious animals that spent most of their time half-submerged in water, grazing on soft aquatic plants. Dinosaurs were also thought to be incredibly stupid in view of their very small braincase. For instance, the plated Stegosaurus had a brain the size of a walnut which is indeed minuscule for an animal reaching 9 m in length. This view on dinosaurs drastically changed starting in the 1960s (the so-called “dinosaur renaissance”) when new discoveries such as the numerous fossils of the duck-billed dinosaur Maiasaura found at “Egg Mountain” in Montana, and encompassing individuals of all ages from hatchlings to adults, purportedly showed that dinosaurs raised their youngs and thus had intelligence matching those of modern mammals and birds. Today, dinosaurs are ubiquitously portrayed as highly active fully terrestrial creatures capable of a wide range of social behavior such as pack hunting and parental care.  

The old view of dinosaurs as dull-witted amphibious beasts has been totally abandoned and these animals are now often seen as one of the prime evolutionary successes rather than as a failed nature experiment doomed for extinction. However, in recent years, scattered discoveries indicated that at least some dinosaurs were aquatic: in the 1970s, a new specimen of the little theropod Compsognathus  found in southern France was described as having webbed feet indicative of a semi-aquatic lifestyle.  In 2010, the analysis of the oxygen isotope ratios in Spinosaurus teeth showed that it was close to those of crocodiles and aquatic turtles, proving that the giant sailed theropod spent lots of time in water. In 2011, a new ceratopsian dinosaur, Koreaceratops, was described as having a tail adapted for swimming. Now, a new study published in the April 2014 issue of the Journal of the Australian Society of Vertebrate Palaeontology, shows that the aquatic lifestyle of dinosaurs was actually widespread. The study applied the same isotopic analysis technique used for Spinosaurus, on the teeth of some 20 species of sauropods (the long-necked, long-tailed giants such as Diplodocus and Brachiosaurus) and ornithopods (including the duck-billed dinosaurs such as Parasaurolophus and  Edmontosaurus) from the Late Jurassic and Late Cretaceous of North America. The results show for all teeth a level of oxygen isotopes compatible with life in water. “This technique has until now only been applied to Spinosaurus because a fish-eating diet was long suspected for this theropod due to its crocodile-like snout. Nobody thought to check on dinosaurs such as Brachiosaurus or Edmontosaurus as the general consensus was that these were fully terrestrial” says lead author Dr. Avril Zierste from the Palaeontology department of the University of Sao Paulo. “The results came quite as a shock because the current views on these ancient creatures will have to take a 180 degree turn”, she adds. Many observed dinosaurian features that were left unexplained as land animals, make perfect sense if they were water dwelling gentle giants. For instance, the flattened tail of duck-billed dinosaurs rigidified by ossified tendons, were superbly adapted for swimming. Moreover the often complex nasal apparatus of many of these same duck-billed dinosaurs were probably used as snorkels to breathe while underwater, as initially hypothesized well before the “dinosaur renaissance". Sauropod bones are well known to show high degree of pneumaticity, which are seen as evidence of the presence of air sacs. This purpose of this becomes clear if these animals were aquatic as air sacs will help with buoyancy and act as floating devices. It is probably not a coincidence that fossils of dinosaurs around the world were predominantly found in regions that were very close to water and often among remains of marine or freshwater animals such as fish and crocodiles.
Old depiction of Brachiosaurus depicted as aquatic animals by Czech painter Z. Burian (1905-1981). New study suggests early paleontologists were right from the beginning about the lifestyle of dinosaurs.


Is it possible that the current view of terrestrial dinosaurs with high metabolism portrayed after  the “dinosaur renaissance” was more based on wishful thinking than hard evidences? The eminent scholar Josh Mothorn certainly thinks so: “We were so keen to believe that no group of animals could have dominated the earth for 165 millions years without sharing at least some of the qualities of our kind, the mammals, such as warm-bloodedness and intelligence, that any circumstances tending to indicate that they were something else than slow moving idiotic monsters, were branded as evidence of complex behavioral habit. The fact is that movies such as “Jurassic Park” would never have been successful if the heroes were confronted not by incredibly fast and skillful killing machines but by clumsy sluggish creatures that could be easily fooled and outsmarted”.  “The dinosaur renaissance is dead” concludes Art Kerbebrok after hearing the conclusions of the study “it is high time that we stop imagining them as nothing more than stupid giants too heavy to support their own weight. People were quick to dismiss the obvious: their brain to body size ratios were among the smallest in any tetrapods. Dinosaurs were slow, gigantic and idiotic. Mammals have outwitted them, that’s why dinosaurs are extinct”.  In light of the new study by Dr. Zierste and co-workers, it seems that the old prevalent view of dinosaur as slow-witted and placid semi-aquatic giants was correct after all.


Reference:
Avril Z., Peter S. G., Robert T. B., Ines L. P., Lambert J. B., Stewart M.T., Fernando E. N., Oviedo T. F., Oscar J., Lewis C. C. (April 1, 2014) “Oxygen isotope analysis and brain-body ratio measurements of 20 species of Sauropoda and Ornithopoda as evidence for semi-aquatic lifestyle and low I.Q. for the clade Dinosauria” J. of Australian Society of Vertebrate Palaeontology, 90., 1-12.

Sunday, March 16, 2014

A unique feeding specialization in a prehistoric porpoise

Life reconstruction of a pair of Semirostrum ceruttii
      Porpoises (Family Phocoenidae) are among the smallest cetaceans (whales). They live in coastal regions, feeding on fish and squids on the sea floor. The six living species of porpoises are distributed in all the oceans of the world. Porpoises  are a quite recent addition to the cetacean world, having diverged from the dolphins probably during the middle of the Miocene period. Fossil porpoises are all very similar to their modern counterparts and do not show much specialization, with the exception of the newly discovered Semirostrum ceruttii from the Pliocene San Diego and Purisima formations of California. 
The Black Skimmer (Rynchops niger) (photo by Dan Pancano)

       Semirostrum is unique among the cetaceans for its nearly toothless lower jaw that is some 40% longer than its upper jaw. The many mandibular canals found in this protruding lower jaw indicate that this was a richly innerved and vascularized area and was most probably used for prey detection. The slightest touch would provoke the immediate closure of the mouth. A modern equivalent of such apparatus is given by the beak of the skimmer (Rhynchops), a tern-like seabird that hunts by flying close to the water surface, skimming the waves with its lower jaw. Semirostrum would have done the same at the bottom of the seafloor in search of small preys living close to the sand surface. This high degree of feeding specialization (called skim-feeding)  is rather unprecedented among mammals. Semirostrum lived alongside other benthic foraging mammals such as the near toothless walrus Valenictus and the baleen whale Herpetocetus, indicating an unique shallow water ecosystem. Semirostrum is known from an almost complete skull and several referred specimens that include postcranial elements.
Semirostrum scale diagram

Ref: Rachel A. Racicot, Thomas A. Deméré, Brian L. Beatty & Robert W. Boessenecker. 2014. Unique Feeding Morphology in a New Prognathous Extinct Porpoise from the Pliocene of California. Current Biology. Published online.

Sunday, February 2, 2014

One crazy Sauropterygian


You won’t believe what crazy prehistoric critter has just been described from the Middle Triassic (Anisian) Luoping fauna of the Yunnan province of China. The site is world famous for his rich collection of well-preserved fossils of shallow sea marine reptiles that include primitive ichthyosaurs, protorosaurs and pachypleurosaurs.

Atopodentatus unicus is a Sauropterygian with a typical body plan of a primitive Sauropterygian, elongated, with a long tail, and paddle-like limbs. However the neck is fairly short and the head minuscule. But what a head! It is from the sort that only a mother could love. The tip of the snout is bent downward and the jaw is filled with numerous needle like teeth. The most bizarre aspect of the snout is that its front is split in two and armed with more teeth forming a kind of non-functional second jaw. This bizarre apparatus has been linked to a very specialized diet. The animal was probably shoveling sand at the bottom of the sea to trap small crustaceans and worms inside the cage made by its delicate teeth.

If you don’t have access to the full paper in Naturwissenshaften, go check Jaime Headden’s blog for a vivid description of the remains of this peculiar critter.


Here is the abstract of the paper:




Abstract

The Luoping fauna (Anisian, Middle Triassic) is probably the oldest of Triassic faunas in Guizhou–Yunnan area, China. The reptilian assemblage is comprised of ichthyosaurs, a number of sauropterygians (pachypleurosaur-like forms), saurosphargids, protorosaurs, and archosauriforms. Here, we report on a peculiar reptile, newly found in this fauna. Its dentition is fence or comb-like and bears more than 175 pleurodont teeth in each ramus of the upper and lower jaws, tooth crown is needle-like distally and blade-shaped proximally; its rostrum strongly bends downward and the anterior end of its mandible expands both dorsally and ventrally to form a shovel-headed structure; and its ungual phalanges are hoof-shaped. The specializations of the jaws and dentition indicate that the reptile may have been adapted to a way of bottom-filter feeding in water. It is obvious that such delicate teeth are not strong enough to catch prey, but were probably used as a barrier to filter microorganisms or benthic invertebrates such as sea worms. These were collected by the specialized jaws, which may have functioned as a shovel or pushdozer (the mandible) and a grasper or scratcher (the rostrum). Our preliminary analysis suggests that the new reptile might be more closely related to the Sauropterygia than to other marine reptiles.


Reference: Cheng, L.; Chen, X.-H.; Shang, Q.-H. and Wu X.C. 2014. A new marine reptile from the Triassic of China, with a highly specialized feeding adaptation. Naturwissenschaften. In press.

Original artworks on Paleoexhibit are copyrighted to Nobu Tamura. Do not use without permission (Email: nobu dot tamura at yahoo dot com)

Wednesday, January 1, 2014

2013 in Paleontology


A selection of species described in 2013
Here is my pick for the top paleontology stories of year 2013 (not in particular order):

Archicebus achilles
1) The discovery in the Hubei province of China of the oldest haplorhine primate skeleton, Archicebus achilles., dating from the Eocene.
Reference: Ni, X.; Gebo, D. L.; Dagosto, M.; Meng, J.; Tafforeau, P.; Flynn, J. J.; Beard, K. C. 2013. The oldest known primate skeleton and early haplorhine evolution. Nature 498 (7452): 60–64.


Entelognathus primordialis

2)Entelognathus primordialis, a Placoderm fish with a modern type jaw that rewrites the history of jaw evolution in vertebrates.
Reference: Zhu, Min; Xiaobo Yu, Per Erik Ahlberg, Brian Choo, Jing Lu, Tuo Qiao, Qingming Qu, Wenjin Zhao, Liantao Jia, Henning Blom & You'an Zhu 2013. A Silurian placoderm with osteichthyan-like marginal jaw bones. Nature (502): 188–193.

3) A new study using computer mechanical simulation coupled with high resolution CT scans has indicated that theropod dinosaur beaks evolved to stabilize the skull during biting and feeding rather than as a lightweight replacement for teeth as previously assumed.
Microraptor gui
Reference: Lautenschlager, Stephan et al. 2013. Edentulism, beaks, and biomechanical innovations in the evolution of theropod dinosaurs. PNAS. in press.

4) Microraptor gets a highlight again with the description of a specimen with fish scales in its abdominal cavity proving that it was an opportunistic feeder that also was also piscivorous.
Reference: Lida Xing et al. 2013. Piscivory in the feathered dinosaur Microraptor. Evolution. 67(8): 2441–2445.

Tsintaosaurus spinorhinus
5) Two familiar duck-billed dinosaurs got facelifts with the redescription of the crest of Tsintaosaurus and the finding of a soft tissue wattle on the head of one well preserved specimen of Edmontosaurus.
Reference: Prieto-Márquez, A.; Wagner J.R. 2013. The ‘Unicorn’ Dinosaur That Wasn’t: A New Reconstruction of the Crest of Tsintaosaurus and the Early Evolution of the Lambeosaurine Crest and Rostrum.. PLoS ONE 8 (11): e82268.

Bell, P. R.; Fanti, F.; Currie, P. J.; Arbour, V. M. 2013. A Mummified Duck-Billed Dinosaur with a Soft-Tissue Cock's Comb. Current Biology. in press.
Edmontosaurus regalis

6) A new methodology has clocked the rate of evolution of arthropods and it was found to be four to five times faster during the so-called "Cambrian explosion" than after it.
Reference: Michael S.Y. Lee, Julien Soubrier, Gregory D. Edgecombe, Rates of Phenotypic and Genomic Evolution during the Cambrian Explosion, Current Biology, Volume 23, Issue 19, 7 October 2013, Pages 1889-1895.

Lythronax argestes
7) At 8 meters in length, the tyrannosaurid Lythronax argestes from the Cretaceous of Utah emerges as the new rising star among the dinosaur enthusiasts and t-rex lovers.
Reference: Loewen, M. A.; Irmis, R. B.; Sertich, J. J. W.; Currie, P. J.; Sampson, S. D. 2013. Tyrant Dinosaur Evolution Tracks the Rise and Fall of Late Cretaceous Oceans. In Evans, David C. PLoS ONE 8 (11): e79420.

8) Three new ceratopsians from North America have been described: Bravoceratops from Texas, Nasutoceratops from Utah and Judiceratops from Montana.
Judiceratops tigris
Reference: Longrich, N. R. 2013. Judiceratops tigris, a New Horned Dinosaur from the Middle Campanian Judith River Formation of Montana. Bulletin of the Peabody Museum of Natural History 54: 51–65.

Sampson, S. D.; Lund, E. K.; Loewen, M. A.; Farke, A. A.; Clayton, K. E. 2013. A remarkable short-snouted horned dinosaur from the Late Cretaceous (late Campanian) of southern Laramidia. Proceedings of the Royal Society B: Biological Sciences 280 (1766): 2013118.

        Wick, S. L.; Lehman, T. M. 2013. A new ceratopsian dinosaur from the Javelina Formation (Maastrichtian) of West Texas and implications for chasmosaurine phylogeny". Naturwissenschaften. in press (7): 667.


Panthera blytheae
9) Panthera blytheae from the Late Miocene of Tibet is the oldest known big cat (genus Panthera) that includes lions, tigers, panthers, leopards and jaguars, and points to an asian origin for them.
Reference: Tseng, Jack; Wang, Xiaoming; Slater, Graham J. ; Takeuchi, Gary T. ; Li, Qiang; Liu, Juan; and  Xie, Guangpu. 2014. Himalayan fossils of the oldest known pantherine establish ancient origin of big cats. Proceedings of the Royal Society B 281 (1774): 20132686.
10) Rock legend Jim Morrison has now a prehistoric animal named after him, the 2 meter long iguana relative, Barbaturex morrisoni.
Barbaturex morrisoni
Reference: Head, J. J.; Gunnell, G. F.; Holroyd, P. A.; Hutchison, J. H.; Ciochon, R. L. 2013. Giant lizards occupied herbivorous mammalian ecospace during the Paleogene greenhouse in Southeast Asia. Proceedings of the Royal Society B: Biological Sciences 280 (1763): 20130665.

Original artworks on Paleoexhibit are copyrighted to Nobu Tamura. Do not use without permission (Email: nobu dot tamura at yahoo dot com)

Tuesday, November 19, 2013

Ajancingenia yanshini

After more than 30 years, the oviraptorid "Ingenia" yanshini finally got a new name: officially, it is now Ajancingenia yanshini. This dinosaur, first described in 1981 by Rinchen Barsbold from a fragmentary skeleton, was originally christened "Ingenia" but this generic name turns out to be preoccupied by a nematode worm therefore necessitating a new denomination. The paper announcing the change of name was published in Zootaxa by one Jesse Easter and all sounded very well until I saw THIS!  Shame on you, Mr Easter, this is not cool... not cool at all.

Ref:

R. Barsbold. 1981. Bezzubyye khishchnyye dinozavry Mongolii [Toothless carnivorous dinosaurs of Mongolia]. Sovmestnaia Sovetsko-Mongol’skaia Paleontologicheskaia Ekspeditsiia Trudy 15:28-39

J. Easter. 2013. A new name for the oviraptorid dinosaur "Ingenia" yanshini (Barsbold, 1981; preoccupied by Gerlach, 1957).  Zootaxa. 3737(2), 184-190.

M. Mortimer. Theropod Database information on "Ingenia" published! ... by someone else

A. Cau. Il preoccupante caso del preoccupato Ingenia [AGGIORNAMENTO]

Original artworks on Paleoexhibit are copyrighted to Nobu Tamura. Do not use without permission (Email: nobu dot tamura at yahoo dot com). Check out my portfolio at spinops.blogspot.com.