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| image_caption = Humerus, [[Deva Natural History Museum]]
| image_caption = Humerus, [[Deva Natural History Museum]]
| authority = [[Friedrich von Huene|von Huene]], [[1932 in paleontology|1932]]
| authority = [[Friedrich von Huene|von Huene]], [[1932 in paleontology|1932]]
| type_species = ''Magyarosaurus dacus''
| subdivision_ranks = [[Species]]
⚫
| type_species_authority = ([[Franz Nopcsa von Felső-Szilvás|Nopcsa]], [[1915 in paleontology|1915]] [originally ''[[Titanosaurus]] dacus''])
| subdivision =
| synonyms_ref = <ref name="codrea2008"/>
⚫
* ''M. dacus'' <small>([[Franz Nopcsa von Felső-Szilvás|Nopcsa]], [[1915 in paleontology|1915]] [originally ''[[Titanosaurus]] dacus'']) ([[Type species|type]])</small>
| synonyms =
⚫
* ''M. hungaricus'' <small>von Huene, 1932</small>
* ''M. transsylvanicus'' <small>von Huene, 1932</small>
''M. hungaricus'' <small>von Huene, 1932</small><br>
⚫
''M. transsylvanicus'' <small>von Huene, 1932</small>
}}
}}


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The [[holotype]], '''BMNH R.3861a''', consists of a set of vertebrae. Numerous other bones have been found, mainly caudal vertebrae but also dorsals and elements of the appendicular skeleton. No remains of skulls are known. There has been a discovery of 14 [[fossil]] eggs which have been attributed to ''Magyarosaurus''.<ref name="geology"/>
The [[holotype]], '''BMNH R.3861a''', consists of a set of vertebrae. Numerous other bones have been found, mainly caudal vertebrae but also dorsals and elements of the appendicular skeleton. No remains of skulls are known. There has been a discovery of 14 [[fossil]] eggs which have been attributed to ''Magyarosaurus''.<ref name="geology"/>

[[Paleontology]] investigations have been carried out at [[Râpa Roșie]] near [[Sebeş]], on the southwestern side of the Transylvanian Basin. The investigations were started in 1969. [[Dinosaur bones]] were reported in earlier investigations. Based on the investigations carried out by Codrea and Dica in 2005, they have assigned the age of these formations to the [[Early Miocene]] age (also conjectured as of Eggenburgian-Ottnangian age). Some of the rare fossils found here are also vertebrates and one of these is of [[sauropod]] caudal vertebra. Paleontologists involved with the studies at Râpa Roșie have also opined that this is the only [[sauropod]] [[genus]] reported at any time in the latest [[Cretaceous]] [[Maastrichtian]] formations in Romania, which could be stated as ''Magyarosaurus''.<ref name="codrea2008"/>


==Description==
==Description==
Line 45: Line 48:


==Paleoecology==
==Paleoecology==
''Magyarosaurus dacus'', and ''M. hungaricus'' are known from the Hațeg Basin, Romania. Also known from the Hațeg Basin are the small, basal [[hadrosauridae|hadrosaurid]] ''[[Telmatosaurus]]''; and the two species of the [[euornithopoda|euornithopod]] ''[[Zalmoxes]]''. Compared to the small ''M. dacus'', ''M. hungaricus'' was relatively large.<ref name="stein2010"/>
''Magyarosaurus dacus'' is known from the Hațeg Basin, Romania. Also known from the Hațeg Basin are the small, basal [[hadrosauridae|hadrosaurid]] ''[[Telmatosaurus]]'';<ref name="stein2010"/> ''[[Struthiosaurus]]'', a small [[nodosauridae|nodosaurid]];<ref name="weishampel2011"/> ''[[Euronychodon]]'', ''[[Richardoestesia]]'', and ''[[Paronychodon]]'', all [[maniraptora]]ns;<ref name="weishampel2011"/> and the two species of the [[euornithopoda|euornithopod]] ''[[Zalmoxes]]''.<ref name="stein2010"/> ''M. sp.'' is known from a vertebrae. The vertebrae was found in the latest Cretaceous of the [[Sebeş Formation]], although it was probably eroded from the [[Şard Formation]] and placed there. Along side ''Magyarosaurus'' existed ''[[Kallokibotion]]'', an ancient [[turtle]];<ref name="codrea2008"/> ''[[Balaur (dinosaur)|Balaur]]'', a two-clawed [[dromaeosaurid]];<ref name="weishampel2011"/> and ''[[Eurazhdarcho]]'', an [[azhdarchidae|azhdarchid]].<ref name="vremir2013"/>


==References==
==References==
<references>
<references>
<ref name="codrea2008">{{cite journal|last=Codrea|first=V.A.|coauthors=Murzea-Jipa, C. & Venczel, M.|year=2008|title=A Sauropod Vertebrae at Râpa Roşie (Alba District)|journal=Acta Palaeontologica Romaniae|volume=6|pages=43–48|url=http://www.geo-paleontologica.org/page8/Codrea_etal.pdf}}</ref>
<ref name=therrienetal2009>Therrien, F., Zelenitsky, D.K. and Weishampel, D.B. (2009). "Palaeoenvironmental reconstruction of the Late Cretaceous Sânpetru Formation (Haţeg Basin, Romania) using paleosols and implications for the "disappearance" of dinosaurs." ''Palaeogeography, Palaeoclimatology, Palaeoecology'', '''272'''(1-2): 37-52. {{doi|10.1016/j.palaeo.2008.10.023}}</ref>
<ref name=therrienetal2009>Therrien, F., Zelenitsky, D.K. and Weishampel, D.B. (2009). "Palaeoenvironmental reconstruction of the Late Cretaceous Sânpetru Formation (Haţeg Basin, Romania) using paleosols and implications for the "disappearance" of dinosaurs." ''Palaeogeography, Palaeoclimatology, Palaeoecology'', '''272'''(1-2): 37-52. {{doi|10.1016/j.palaeo.2008.10.023}}</ref>
<ref name=curryrogers2005>Curry Rogers, K. (2005). "Titanosauria: A phylogenetic Overview" ''in'' Curry Rogers, K. and Wilson, J.A. (eds), ''The Sauropods: Evolution and Paleobiology''. Berkeley: University of California Press. ISBN 0-520-24623-3</ref>
<ref name=curryrogers2005>Curry Rogers, K. (2005). "Titanosauria: A phylogenetic Overview" ''in'' Curry Rogers, K. and Wilson, J.A. (eds), ''The Sauropods: Evolution and Paleobiology''. Berkeley: University of California Press. ISBN 0-520-24623-3</ref>
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<ref name=dwarfism>{{cite journal|last1=Stein|first1=K.|last2=Csiki|first2=Z.|last3=Curry Rogers|first3=K.|last4=Weishampel|first4=D.B.|last5=Redelstorff|first5=R.|coauthors=Carballido, J.L. & Sander, P.M.|year=2010|url=http://www.pnas.org/content/107/20/9258.full.pdf+html|title=Small body size and extreme cortical bone remodeling indicate phyletic dwarfism in ''Magyarosaurus dacus'' (Sauropoda: Titanosauria)|journal=Proceedings of the National Academy of Sciences|volume=107|issue=20|pages=9258–9263|doi=10.1073/pnas.1000781107}}</ref>
<ref name=dwarfism>{{cite journal|last1=Stein|first1=K.|last2=Csiki|first2=Z.|last3=Curry Rogers|first3=K.|last4=Weishampel|first4=D.B.|last5=Redelstorff|first5=R.|coauthors=Carballido, J.L. & Sander, P.M.|year=2010|url=http://www.pnas.org/content/107/20/9258.full.pdf+html|title=Small body size and extreme cortical bone remodeling indicate phyletic dwarfism in ''Magyarosaurus dacus'' (Sauropoda: Titanosauria)|journal=Proceedings of the National Academy of Sciences|volume=107|issue=20|pages=9258–9263|doi=10.1073/pnas.1000781107}}</ref>
<ref name="geology">"Briefing", ''Geology Today'' '''7'''(1): p. 2-6.</ref>
<ref name="geology">"Briefing", ''Geology Today'' '''7'''(1): p. 2-6.</ref>
<ref name="weishampel2011">{{cite book|authors=Weishampel, D.B. & Jianu, C.M.|year=2011|title=Transsylvanian Dinosaurs|publisher=The John Hopkins University Press|pages=37–38|isbn=1-4214-0027-8}}</ref>
<ref name="vremir2013">{{Cite doi|10.1371/journal.pone.0054268}}</ref>
</references>
</references>


Revision as of 15:27, 28 January 2014

Magyarosaurus
Temporal range: Late Cretaceous, 70 Ma
↓
Humerus, Deva Natural History Museum
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: †Sauropodomorpha
Clade: †Sauropoda
Clade: †Macronaria
Clade: †Titanosauria
Clade: †Lithostrotia
Genus: †Magyarosaurus
von Huene, 1932
Type species
Magyarosaurus dacus
(Nopcsa, 1915 [originally Titanosaurus dacus])
Synonyms[1]

M. hungaricus von Huene, 1932
M. transsylvanicus von Huene, 1932

Magyarosaurus ("Magyar lizard") is a genus of dwarf sauropod dinosaur from late Cretaceous Period (early Maastrichtian[2]) in what is now Romania. It is one of the smallest-known adult sauropods, measuring only six meters in length. The type species is Magyarosaurus dacus. Magyarosaurus was found to be a close relative of Rapetosaurus in the family Saltasauridae in the sauropod clade Titanosauria in a 2005 study of the titanosaurs by Kristina Curry Rogers.[3]

Discovery

Magyarosaurus sp. scapula

Remains belonging to at least ten individuals have been recovered from the Hunedoara region (Sânpetru Formation) in the area which is now western Romania. Initially they were named Titanosaurus dacus, the specific name referring to the Dacians (who had lived in that place about 2000 years ago), by Baron Nopcsa in 1915.[4] Nopcsa had collected fossils in the area since 1895. The species was later renamed Magyarosaurus dacus by Friedrich von Huene in 1932.[5] Von Huene in 1932 also named two other species: M. hungaricus and M. transsylvanicus. Larger, rarer M. hungaricus may represent a distinct taxon.[6]

The holotype, BMNH R.3861a, consists of a set of vertebrae. Numerous other bones have been found, mainly caudal vertebrae but also dorsals and elements of the appendicular skeleton. No remains of skulls are known. There has been a discovery of 14 fossil eggs which have been attributed to Magyarosaurus.[7]

Paleontology investigations have been carried out at Râpa Roșie near Sebeş, on the southwestern side of the Transylvanian Basin. The investigations were started in 1969. Dinosaur bones were reported in earlier investigations. Based on the investigations carried out by Codrea and Dica in 2005, they have assigned the age of these formations to the Early Miocene age (also conjectured as of Eggenburgian-Ottnangian age). Some of the rare fossils found here are also vertebrates and one of these is of sauropod caudal vertebra. Paleontologists involved with the studies at Râpa Roșie have also opined that this is the only sauropod genus reported at any time in the latest Cretaceous Maastrichtian formations in Romania, which could be stated as Magyarosaurus.[1]

Description

Magyarosaurus was estimated to be 1.1 metric tons (1.1 long tons; 1.2 short tons) in weight.[8] It carried strange dermal armour.[9][10]

Distinguishing characteristics

Stein et al. (2010) found a few distinguishing characteristics of Magyarosaurus. They are listed below:[11]

  • for its clade, it has a small size;
  • and a small medullary cavity and relatively thick cortex.

Paleobiology

Dwarfism

Size compared with a human

The islands it inhabited led to Magyarosaurus becoming a product of insular dwarfism as a result of selective pressures presented by limited food supplies and a lack of predators, all favoring a smaller body size.[6] This is seen in many other dinosaurs existing at the time, including the ornithopod Rhabdodon and the nodosaur Struthiosaurus. Hatzegopteryx, however, grew to giant sizes and preyed on Magyarosaurus.[8] Nopcsa was the first to suggest island dwarfism as an explanation for the small size of Magyarosaurus compared to other sauropods. Later researchers doubted his conclusions, suggesting instead that the known Magyarosaurus fossil represented juveniles. However, a detailed study of bone growth patterns published in 2010 supported Nopcsa's original hypothesis, showing that the small Magyarosaurus individuals were adults.[6][8] Island dwarfism has been suggested to has led to isolated genera retaining more primitive characteristics.[9]

Armour

An osteoderm discovered in the "La Cãrare" locality. The locality is near Sînpetru village, in the Hațeg Basin of Romania. The osteoderm was assigned to Magyarosaurus dacus. This shows that dermal armour had a wide distribution in these Late Cretaceous sauropods.[10] The osteoderms was peculiar in shape and size,[10] and led to eggs being assigned to its family, Nemegtosauridae, and possibly to Magyarosaurus.[9]

Possible eggs

Lithostrotian eggs have been assigned to Nemegtosauridae. The eggs possibly persist to either Magyarosaurus dacus or Paludititan, the former being more likely.[9] The Hațeg Basin was a large nesting place in the late Cretaceous, and is served as that for hadrosaurids, and titanosaurs. 11 eggs have been assigned to Nemegtosauridae, all from the Sânpetru Formation.[9] Embryos were preserved inside the eggs, and one egg shows proof of dermal armouring.[9]

The eggs were uncovered in 2001, during a field expedition by a Belgo-Romanian team. They were originally identified as in nests, but now it has been shown that no nesting structures has been preserved.[9]

Paleoecology

Magyarosaurus dacus is known from the Hațeg Basin, Romania. Also known from the Hațeg Basin are the small, basal hadrosaurid Telmatosaurus;[11] Struthiosaurus, a small nodosaurid;[12] Euronychodon, Richardoestesia, and Paronychodon, all maniraptorans;[12] and the two species of the euornithopod Zalmoxes.[11] M. sp. is known from a vertebrae. The vertebrae was found in the latest Cretaceous of the Sebeş Formation, although it was probably eroded from the Şard Formation and placed there. Along side Magyarosaurus existed Kallokibotion, an ancient turtle;[1] Balaur, a two-clawed dromaeosaurid;[12] and Eurazhdarcho, an azhdarchid.[13]

References

  1. ^ a b c Codrea, V.A. (2008). "A Sauropod Vertebrae at Râpa Roşie (Alba District)" (PDF). Acta Palaeontologica Romaniae. 6: 43–48. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  2. ^ Therrien, F., Zelenitsky, D.K. and Weishampel, D.B. (2009). "Palaeoenvironmental reconstruction of the Late Cretaceous Sânpetru Formation (Haţeg Basin, Romania) using paleosols and implications for the "disappearance" of dinosaurs." Palaeogeography, Palaeoclimatology, Palaeoecology, 272(1-2): 37-52. doi:10.1016/j.palaeo.2008.10.023
  3. ^ Curry Rogers, K. (2005). "Titanosauria: A phylogenetic Overview" in Curry Rogers, K. and Wilson, J.A. (eds), The Sauropods: Evolution and Paleobiology. Berkeley: University of California Press. ISBN 0-520-24623-3
  4. ^ Nopcsa, F. (1915). "Die Dinosaurier der siebenburgischen Landesteile Ungarns." UNGAR. GEOL. REICHSANST., 23: 1-26.
  5. ^ von Huene, F. (1932). "Die fossile Reptil-Ordnung Saurischia, ihre Entwicklung und Geschichte." Mong. Geol. Pal., 4(1) pts. 1 and 2, viii +361 pp.
  6. ^ a b c Stein, K.; Csiki, Z.; Curry Rogers, K.; Weishampel, D.B.; Redelstorff, R. (2010). "Small body size and extreme cortical bone remodeling indicate phyletic dwarfism in Magyarosaurus dacus (Sauropoda: Titanosauria)". Proceedings of the National Academy of Sciences. 107 (20): 9258–9263. doi:10.1073/pnas.1000781107. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  7. ^ "Briefing", Geology Today 7(1): p. 2-6.
  8. ^ a b c Scott, C. (2012). "Change of Die". Planet Dinosaur. Firefly Books. pp. 200–208. ISBN 978-1-77085-049-1. {{cite book}}: Unknown parameter |editors= ignored (|editor= suggested) (help)
  9. ^ a b c d e f g Grellet-Tinner, G; Codrea, V; Folie, A (2012). Andrew A. Farke (ed.). "First evidence of reproductive adaptation to "island effect" of a dwarf Cretaceous Romanian titanosaur, with embryonic integument in ovo". PLoS ONE. 7 (3): e32051. doi:10.1371/journal.pone.0032051. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)CS1 maint: unflagged free DOI (link)
  10. ^ a b c Csiki, Z. (1999). "New evidence of armoured titanosaurids in the Late Cretaceous - Magyarosaurus dacus from the Hateg Basin (Romania)". Oryctos. 2: 93–99.
  11. ^ a b c Stein, K.; Csiki, Z.; Curry Rogers, K.; Weishampel, D.B.; Redelstorff, R. (2010). "Small body size and extreme cortical bone remodeling indicate phyletic dwarfism in Magyarosaurus dacus (Sauropoda: Titanosauria)". Proceedings of the National Academy of Sciences of the United States of America. 20. 107: 9258–9263. doi:10.1073/pnas.1000781107. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  12. ^ a b c Transsylvanian Dinosaurs. The John Hopkins University Press. 2011. pp. 37–38. ISBN 1-4214-0027-8. {{cite book}}: Cite uses deprecated parameter |authors= (help)
  13. ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1371/journal.pone.0054268, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1371/journal.pone.0054268 instead.

External links

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