Zalmoxes

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Zalmoxes
Temporal range: Maastrichtian
70–66  Ma
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Zalmoxes shqiperorum.jpg
Skeleton of Zalmoxes shqiperorum in Brussels
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade:† Ornithischia
Clade:† Ornithopoda
Family:† Rhabdodontidae
Genus:† Zalmoxes
Weishampel et al. 2003
Type species
†Zalmoxes robustus
Species
  • †Z. robustus(Nopcsa, 1899)
  • †Z. shqiperorumWeishampel et al., 2003
Synonyms

Zalmoxes is a genus of rhabdodontid ornithopod dinosaur from the Maastrichtian age of the Late Cretaceous in what is now Romania. The genus is known from specimens first named as the species Mochlodon robustum in 1899 by Franz Nopcsa before being reclassified as Rhabdodon robustum by him in 1915. In 1990, this name was corrected to Rhabdodon robustus by George Olshevsky and, in 2003, the species was once more reclassified as the type species Zalmoxes robustus. Zalmoxes refers to the Dacian deity Zalmoxis and robustus refers to the robustness of the remains. Also in 2003, another species was named, Zalmoxes shqiperorum, named for the Albanian name for Albanians.

Contents

History of discovery

Skull of Zalmoxes shqiperorum Zalmoxes shqiperorum 1.jpg
Skull of Zalmoxes shqiperorum

Zalmoxes was first known from numerous fossils found in Transylvania, which were named as the species Mochlodon robustus by Baron Franz Nopcsa in 1899. The specific name referred to its robust build. [1] In 1915, Nopcsa renamed the species to Rhabdodon robustum, amended in 2003 by David B. Weishampel, Coralia-Maria Jianu, Zoltan Csiki, and David B. Norman. Weishampel et al. (2003) published a paper on new remains from Romania, which they found to represent a new species. They found R. robustus was sufficiently different from Rhabdodon and named the new genus Zalmoxes for the former. The genus refers to the Thracian deity Zalmoxis (sometimes spelled Zalmoxes), who retreated for three years in a crypt to be resurrected on the fourth year. Likewise, the animal Zalmoxes had been liberated from its fossil grave to attain taxonomic immortality. The naming article further explained this by referring to a Greek legend according to which Zalmoxes was a slave of Pythagoras, when he travelled to Dacia and was deified by the Dacian people. In addition, Weishampel et al. named the new specimens Zalmoxes shqiperorum, after Shqiperia, the Albanian name for Albania, with which Nopcsa had a special relationship. [2] One specimen now belongs to Telmatosaurus , while another specimen is also suspected to belong to that genus based on similar basicrania morphology. [3]

Description

Illustrations of Z. robustus and Z. shqiperorum in scale Zalmoxes dichotomy.jpg
Illustrations of Z. robustus and Z. shqiperorum in scale

Zalmoxes is a rather small genus of bipedal herbivore with a large triangular head and a beak. [2] Z. shqiperorum is the larger species, known from a subadult 2.5 m (8.2 ft) long, as well as an early juvenile 1.2 m (3.9 ft) in length, while Z. robustus subadults range from 2–2.4 m (6.6–7.9 ft) long. [4] An adult Z. robustus would have measured up to 2.5 m (8.2 ft) in length and 45 kg (99 lb) in body mass. [5] An unnamed species of Zalmoxes, is known from larger sizes, with an adult 2.9 m (9.5 ft) in length. Although Nopcsa thought the small size of Zalmoxes was due to island dwarfism, Attila Ösi and colleagues found it was closer to the size of the rhabdodontid ancestor, with larger Rhabdodon and smaller Mochlodon having island gigantism and island dwarfism respectively. However, when the species of Zalmoxes are taken into account separately, it can be seen than Z. shqiperorum continued the general size trend from Orodromeus to Tenontosaurus , while Z. robustus may have had slight nanism. [4] Zalmoxes had a relatively slow growth rate and long growth period, suggesting that this dinosaur may have had a unique growth strategy. [6]

Zalmoxes robustus (purple) compared in size to a human and other iguanodonts Iguanodontian Sizes.svg
Zalmoxes robustus (purple) compared in size to a human and other iguanodonts

Z. robustus is known from about 80% of the skull. However, no complete articulated skull is known, and most of the bones do not overlap and are found in isolation. Weishampel et al. found that these likely represented one individual, as the bones were from the same formation and are the same colour. Four individuals were identified by Nopcsa for Z. robustus, and from these it can be seen that there is skeletal variation in the species. Like with the cranial material, vertebrae of Z. robustus are often found isolated. All regions of the vertebral column are represented in the fossil record, although no sternal plates have been found yet. The sacrum includes three vertebrae, with two sacrodorsals (dorsal vertebrae in the sacrum) and three sacrocaudals (caudal vertebrae in the sacrum). The limb and girdle bones are also well represented, with only the hands (manus) and feet (pes) mostly lacking. [2]

While more poorly known than Z. robustus, Z. shqiperorum is still known from a relatively large amount of the skeleton. Only two mostly complete skeletons are known, the holotype adult, and a referred juvenile. The lower jaw (dentary) of Z. shqiperorum is relatively shorter than the equivalent in Z. robustus, although it is much larger. Ossified tendons are known from the juvenile specimen, showing that they were circular or elliptical in cross section and have fine striations in Z. shqiperorum. Cervical, dorsal and caudal vertebrae are known from Z. shqiperorum, although the former two are only represented by juvenile material. A complete articulated sacrum is known for Z. shqiperorum, with three vertebrae and at least two sacrodorsals. No manual material is known from the species, although a metatarsal and a few phalanges are known. [2]

Classification

Articulated sacrum of Zalmoxes Zalmoxes sacrum.jpg
Articulated sacrum of Zalmoxes

The species of Mochlodon, Rhabdodon and Zalmoxes had long had an uncertain phylogenetic placement, being referred to various families. Nopcsa (1901) also had referred the genus to Hypsilophodontidae, and he suggested affinities with Camptosaurus in 1902, 1904 and 1915. Nopcsa (1915) also realized that Rhabdodon and Mochlodon may be congeneric, placing the complex in Camptosauridae. [2]

For the next half-century, taxonomic workers found Rhabdodon and Mochlodon within either Camptosauridae or Iguanodontidae. However, Paul Sereno (1986) found that Rhabdodon and Mochlodon were within Iguanodontia. The ICZN (1988) resolved this complication, selecting the ornithopod Rhabdodon as having priority over Mochlodon. From this publication, scientists began placing Rhabdodon and Mochlodon within Euornithopoda. In 2003, Weishampel et al. named a new family for Mochlodon, Rhabdodon and the new genus Zalmoxes. This family, Rhabdodontidae, was placed as a derived within Iguanodontia. [2] Further studies support this placement of Rhabdodontidae, phylogenetically between Talenkauen and Tenontosaurus . [4] [7]

Below are two possible phylogenies of Rhabdodontidae by McDonald et al. (2010; left), [7] and Ösi et al. (2012; right). [4]

Ornithopoda

Paleobiology

Zalmoxes has a more robust build than its precursors and more derived relatives. Infraspecific ontogenetic growth is relatively well known in Zalmoxes as there is juvenile material known for the species. Nopcsa proposed that the animals of the Hateg Basin, which were smaller than their relatives elsewhere, adapted through insular dwarfism. [2] Fossils of both species of Zalmoxes have been unearthed in the Sânpetru Formation, the Sebes Formation and Densuş-Ciula Formation in Romania, both species have been found exclusively in the Hateg Island region. [8]

Diet

A scientific paper from 2003 found that Zalmoxes most likely had a diet that consisted of tough fibrous plants like soft shoots, horsetails, angiosperms, pteridophytes, and ferns. [9]

Related Research Articles

<span class="mw-page-title-main">Franz Nopcsa von Felső-Szilvás</span> Hungarian noble and academic

Baron Franz Nopcsa von Felső-Szilvás was a Hungarian aristocrat, adventurer, scholar, geologist, paleontologist and albanologist. He is widely regarded as one of the founders of paleobiology, and first described the theory of insular dwarfism. He was also a specialist on Albanian studies and completed the first geological map of northern Albania.

<i>Camptosaurus</i> Extinct genus of dinosaurs

Camptosaurus is a genus of plant-eating, beaked ornithischian dinosaurs of the Late Jurassic period of western North America and possibly also Europe. The name means 'flexible lizard'.

Professor David Bruce Weishampel is an American palaeontologist in the Center for Functional Anatomy and Evolution at Johns Hopkins University School of Medicine. Weishampel received his Ph.D. in Geology from the University of Pennsylvania in 1981. His research focuses include dinosaur systematics, European dinosaurs of the Late Cretaceous, jaw mechanics and herbivory, cladistics and heterochrony and the history of evolutionary biology. Weishampel's best known published work is The Dinosauria University of California Press; 2nd edition. He consulted for Jurassic Park and is a good friend of Steven Spielberg. He has received an Academy Scientific and Technical Award.

<i>Magyarosaurus</i> Extinct genus of dinosaurs

Magyarosaurus is a genus of dwarf sauropod dinosaur from late Cretaceous Period in Romania. It is one of the smallest-known adult sauropods, measuring only 6 m (20 ft) in length and 750–1,000 kg (1,650–2,200 lb) in body mass. The type and only certain species is Magyarosaurus dacus. It has been found to be a close relative of Rapetosaurus in the family Saltasauridae in the sauropod clade Titanosauria in a 2005 study.

<i>Rhabdodon</i> Extinct genus of dinosaurs

Rhabdodon is a genus of ornithopod dinosaur that lived in Europe approximately 70-66 million years ago in the Late Cretaceous. It is similar in build to a very robust "hypsilophodont", though all modern phylogenetic analyses find this to be an unnatural grouping, and Rhabdodon to be a basal member of Iguanodontia. It was large amongst its relatives, measuring 4 m (13 ft) long and weighing 250 kg (550 lb), with some specimens possibly reaching up to 6 m (20 ft) long.

<span class="mw-page-title-main">Dinosaurs of Romania</span>

The dinosaurs of Romania are mostly Cretaceous in age, though a series of footprints referred to Parabrontopodus mcintoshi was described from the Early Jurassic of Anina, southwestern Romania. Lowermost Cretaceous dinosaurs come from a bauxite mine in the Bihor County that has yielded thousands of disarticulated bones. Uppermost Cretaceous dinosaurs have been known from the Hațeg Basin since the end of the 19th century, mostly as bone concentrations ; more recently, nests with dinosaur eggs, including hatchlings, have been found in Hațeg. Although separated by a gap of approximately 60 million years, the two dinosaur faunas from Romania share some common features: predominance of ornithopods, absence of large theropods, and, in general, the small size of the individuals.

<i>Anoplosaurus</i> Extinct genus of dinosaurs

Anoplosaurus is an extinct genus of herbivorous nodosaurid dinosaur, from the late Albian-age Lower Cretaceous Cambridge Greensand of Cambridgeshire, England. It has in the past been classified with either the armored dinosaurs or the ornithopods, but current thought has been in agreement with the "armored dinosaur" interpretation, placing it in the Ankylosauria.

<i>Elopteryx</i> Extinct genus of dinosaurs

Elopteryx is a genus of, perhaps troodontid, maniraptoran theropod dinosaur based on fragmentary fossils found in late Cretaceous Period rocks of Romania. The single species, Elopteryx nopcsai, is known only from very incomplete material, and therefore is considered a nomen dubium by most paleontologists.

<i>Telmatosaurus</i> Extinct genus of dinosaurs

Telmatosaurus is a genus of basal hadrosauromorph dinosaur from the Late Cretaceous of Romania. It was a relatively small hadrosaur, measuring approximately 5 m (16 ft) in length and 600 kg (1,300 lb) in body mass, which has been explained as an instance of insular dwarfism.

<i>Mochlodon</i> Extinct genus of dinosaurs

Mochlodon is a genus of rhabdodontid dinosaurs from the Late Cretaceous of Austria and Hungary. It lived during the Late Cretaceous and two species are known: M. suessi and M. vorosi.

Rhadinosaurus is a genus of nodosaurid ankylosaur first described in 1881 by Harry Govier Seeley, based on remains uncovered in Austria sometime between 1859 and 1870 by Edward Suess and Pawlowitsch. It was a herbivore that lived around 84.9 to 70.6 million years ago. The type species is R. alcimus.

<i>Orthomerus</i> Extinct genus of dinosaurs

Orthomerus is a genus of dubious hadrosaurid dinosaur from the Late Cretaceous of the Netherlands. It is today an obscure genus, but in the past was conflated with the much better known Telmatosaurus.

<span class="mw-page-title-main">Hațeg Island</span> Prehistoric island

Hațeg Island was a large offshore island in the Tethys Sea which existed during the Late Cretaceous period, probably from the Cenomanian to the Maastrichtian ages. It was situated in an area corresponding to the region around modern-day Hațeg, Hunedoara County, Romania. Maastrichtian fossils of small-sized dinosaurs have been found in the island's rocks. It was formed mainly by tectonic uplift during the early Alpine orogeny, caused by the collision of the African and Eurasian plates towards the end of the Cretaceous. There is no real present-day analog, but overall, the island of Hainan is perhaps closest as regards climate, geology and topography, though still not a particularly good match. The vegetation, for example, was of course entirely distinct from today, as was the fauna.

<i>Hatzegopteryx</i> Genus of large azhdarchid pterosaur from the Late Cretaceous

Hatzegopteryx is a genus of azhdarchid pterosaur found in the late Maastrichtian deposits of the Densuş Ciula Formation, an outcropping in Transylvania, Romania. It is known only from the type species, Hatzegopteryx thambema, named by Buffetaut et al. in 2002 based on parts of the skull and humerus. Additional specimens, including a neck vertebra, were later placed in the genus, representing a range of sizes. The largest of these remains indicate it was among the biggest pterosaurs, with an estimated wingspan of 10 to 12 metres.

<span class="mw-page-title-main">Rhabdodontidae</span> Extinct family of dinosaurs

Rhabdodontidae is a family of herbivorous iguanodontian ornithopod dinosaurs whose earliest stem members appeared in the middle of the Lower Cretaceous. The oldest dated fossils of these stem members were found in the Barremian Castrillo de la Reina Formation of Spain, dating to approximately 129.4 to 125.0 million years ago. With their deep skulls and jaws, Rhabdodontids were similar to large, robust iguanodonts. The family was first proposed by David B. Weishampel and colleagues in 2003. Rhabdodontid fossils have been mainly found in Europe in formations dating to the Late Cretaceous.

<i>Paludititan</i> Extinct genus of dinosaurs

Paludititan is a genus of titanosaurian sauropod dinosaur which lived in the area of present Romania during the Late Cretaceous. It existed in the island ecosystem known as Hațeg Island.

<span class="mw-page-title-main">Rhabdodontomorpha</span> Clade of iguanodont dinosaurs

Rhabdodontomorpha is a clade of basal iguanodont dinosaurs. This group was named in 2016 in the context of the description, based on Spanish findings of an early member of the Rhabdodontidae. A cladistic analysis was conducted in which it was found that Muttaburrasaurus was the sister species of the Rhabdodontidae sensu Weishampel. Therefore, Paul-Emile Dieudonné, Thierry Tortosa, Fidel Torcida Fernández-Baldor, José Ignacio Canudo and Ignacio Díaz-Martínez defined Rhabdodontomorpha as a nodal clade: the group consisting of the last common ancestor of Rhabdodon priscus Matheron, 1869 and Muttaburrasaurus langdoni Bartholomai and Molnar, 1981; and all its descendants. Within the clade Zalmoxes and Mochlodon are also included. The clade is characterized by the following synapomorphies:

<i>Matheronodon</i> Extinct genus of dinosaurs

Matheronodon is a genus of rhabdodontid ornithopod dinosaur from the late Cretaceous Period of the Grès à Reptiles Formation in France. The genus contains a single species, M. provincialis, which is known from a single maxilla and associated teeth. It was named by Pascal Godefroit and colleagues in 2017. The teeth of Matheronodon are large but few in number. The teeth are also in an unusual arrangement, emerging alternatingly from one of a pair of fused tooth sockets in its mouth. In life, the teeth would have functioned like a pair of scissors, allowing Matheronodon to feed on the tough leaves of monocot plants.

<i>Pareisactus</i> Extinct genus of reptiles

Pareisactus is a genus of rhabdodontid ornithopod dinosaur from the Late Cretaceous Conquès Member of the Tremp Formation in the Southern Pyrenees of Spain. The type and only species is P. evrostos, known only from a single scapula.

Transylvanosaurus is an extinct genus of rhabdodontid ornithopod dinosaur from the Late Cretaceous (Maastrichtian) Hateg Basin of Romania. The type species is Transylvanosaurus platycephalus, known from a fragmentary skull.

References

  1. ↑ Nopcsa, F. (1899). "Dinosaurierreste aus Siebenbürgen (Schädel von Limnosaurus transsylvanicus nov. gen. et spec.), Denkschriften der Kaiserlichen Akademie der Wissenschaften". Mathematisch-Naturwissenschaftliche Classe. 68: 555–591.
  2. 1 2 3 4 5 6 7 Weishampel, D.B.; Jianu, C.-M.; Csiki, Z.; Norman, D.B. (2003). "Osteology and phylogeny of Zalmoxes (n. g.), an unusual euornithopod dinosaur from the Latest Cretaceous of Romania". Journal of Systematic Palaeontology. 1 (2): 65–123. doi:10.1017/S1477201903001032. S2CID   86339025.
  3. ↑ Augustin, F.J.; Dumbravă, M.D.; Bastiaans, D.; Csiki-Sava, Z. (2022). "Reappraisal of the braincase anatomy of the ornithopod dinosaurs Telmatosaurus and Zalmoxes from the Upper Cretaceous of the Haţeg Basin (Romania) and the taxonomic reassessment of some previously referred specimens". PalZ. doi: 10.1007/s12542-022-00621-x .
  4. 1 2 3 4 Ősi, A.; Prondvai, E.; Butler, R.; Weishampel, D. B. (2012). Evans, Alistair Robert (ed.). "Phylogeny, Histology and Inferred Body Size Evolution in a New Rhabdodontid Dinosaur from the Late Cretaceous of Hungary". PLOS ONE. 7 (9): e44318. Bibcode:2012PLoSO...744318O. doi: 10.1371/journal.pone.0044318 . PMC   3448614 . PMID   23028518.
  5. ↑ Paul, Gregory S. (2016). The Princeton Field Guide to Dinosaurs. Princeton University Press. p. 312. ISBN   978-1-78684-190-2. OCLC   985402380.
  6. ↑ Csiki, Z.; Redelstorff, R.; Grigorescu, D. (2009). "Bone histology in the Ornithopods from the Maastrichtian of Haţeg Basin – were these dinosaurs really dwarfs?". In Bucur, I.I.; Săsăran, E.; Popyear, D. (eds.). Proceedings of the 7th Romanian Symposium on Paleontology, Cluj-Napoca, 22-24 October 2009 (PDF). Vol. 7. Cluj University Press. pp. 31–32. doi:10.13039/501100000780. OCLC   800980988.
  7. 1 2 McDonald, A. T.; Kirkland, J. I.; Deblieux, D. D.; Madsen, S. K.; Cavin, J.; Milner, A. R. C.; Panzarin, L. (2010). Farke, Andrew Allen (ed.). "New Basal Iguanodonts from the Cedar Mountain Formation of Utah and the Evolution of Thumb-Spiked Dinosaurs". PLOS ONE. 5 (11): e14075. Bibcode:2010PLoSO...514075M. doi: 10.1371/journal.pone.0014075 . PMC   2989904 . PMID   21124919.
  8. ↑ Godefroit, Pascal; Codrea, Vlad; Weishampel, David B. (30 September 2009). "Osteology of Zalmoxes shqiperorum (Dinosauria, Ornithopoda), based on new specimens from the Upper Cretaceous of Nalat-Vad (Romania)". Geodiversitas. 31 (3): 525–553. doi:10.5252/g2009n3a3. S2CID   131476195 . Retrieved 30 October 2020.
  9. ↑ Weishampel, Dave; Csiki-Sava, Zoltan; Norman, David (January 2003). "Osteology and phylogeny of Zalmoxes (n. g.), an unusual Euornithopod dinosaur from the latest Cretaceous of Romania". Journal of Systematic Palaeontology. 1 (2): 65–123. doi:10.1017/S1477201903001032. S2CID   86339025 . Retrieved 24 February 2021.
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