鴕龍的三個有效種彼此有差異,如奧地利種體型小於川斯瓦尼亞種,頸椎也沒後者那麼細長;川斯瓦尼亞種的方骨-副嗅突(quadrate-paroccipital process )連接處癒合,而奧地利種的沒有癒合;朗格多克種頭骨未知,但其與川斯瓦尼亞種的差異在於背椎形狀較平坦;朗格多克種與奧地利種的差異在於坐骨形狀。[9]
鴕龍的支序分類學分析顯示牠是結節龍科的基礎物種,且可能是甲龍亞目中最基礎的物種之一。Ösi(2005)敘述匈牙利龍的論文中,發現雖然鴕龍的生存年代比大部分其他結節龍科還晚,卻是最基礎的物種之一,但還有許多特徵尚未釐清。[13]以下演化樹取自湯普森(Richard S. Thompson)、帕里許(Jolyon C. Parish)、梅德曼(Susannah C. R. Maidment)、巴雷特(Paul M. Barrett)2011年的系統發生學研究[14]
^F. Nopcsa, 1915, "Die dinosaurier der Siebenbürgischen landesteile Ungarns", Mitteilungen aus dem Jahrbuche der Königlich-Ungarischen Geologischen Reichsanstalt23: 1-24
^G. Garcia and X. Pereda-Suberbiola, 2003, "A new species of Struthiosaurus (Dinosauria: Ankylosauria) from the Upper Cretaceous of Villeveyrac (southern France)", Journal of Vertebrate Paleontology23(1): 156-165
^Kirkland, J. I.; Alcalá, L.; Loewen, M. A.; Espílez, E.; Mampel, L.; Wiersma, J. P. (2013). Butler, Richard J, ed. "The Basal Nodosaurid Ankylosaur Europelta carbonensis n. gen., n. sp. From the Lower Cretaceous (Lower Albian) Escucha Formation of Northeastern Spain". PLoS ONE 8 (12): e80405.
^H.G. Seeley, 1881, "The reptile fauna of the Gosau Formation preserved in the Geological Museum of the University of Vienna", Quarterly Journal of the Geological Society of London37(148): 620-707
^F. Nopcsa, 1918, "Leipsanosaurus n. gen. ein neuer thyreophore aus der Gosau", Földtani Közlöny48: 324-328
^Pereda-Suberbiola, X., and Galton, P. M., 2001. Reappraisal of the nodosaurid ankylosaur Struthiosaurus austriacus Bunzel, 1871 from the Upper Cretaceous Gosau Beds of Austria. pp. 173-210 In: Carpenter, K., (ed.) The Armored Dinosaurs. Indiana University Press, Bloomington & Indianapolis, 2001, pp. xv-526
^F. Nopcsa. 1902. "Notizen über cretacische Dinosaurier". Sitzungsberichte der Mathematisch-Naturwissenschaftlichen Classe der Kaiserlichen Akademie der WissenschaftenIII(1): 93-114
^Nopcsa, B.F. Palaeontological notes on reptiles. V. On the skull of the Upper Cretaceous dinosaur Euoplocephalus. Geologica Hungarica, Series Palaeontologica. 1928, 1 (1): 1–84.
^W.P. Coombs. 1978. "Forelimb muscles of the Ankylosauria (Reptilia, Ornithischia)". Journal of Paleontology52(3): 642-657
^Ösi, A. Hungarosaurus tormai, a new ankylosaur (Dinosauria) from the Upper Cretaceous of Hungary. Journal of Vertebrate Paleontology. 2005, 25 (2): 370–383. doi:10.1671/0272-4634(2005)025[0370:HTANAD]2.0.CO;2.
^Richard S. Thompson; Jolyon C. Parish; Susannah C. R. Maidment; Paul M. Barrett. Phylogeny of the ankylosaurian dinosaurs (Ornithischia: Thyreophora). Journal of Systematic Palaeontology. 2011, 10 (2): 301–312. S2CID 86002282. doi:10.1080/14772019.2011.569091.
Bunzel, E. 1871. Die Reptilifauna der Gosaformationin in der Neuen Welt bei Weiner-Neustadt. Abhand. Geol. Reichsanst. Wein 5:1-18.
Osi, Attila. 2005. Hungarosaurus tormai, a new ankylosaur (Dinosauria) from the Upper Cretaceous of Hungary. Journal of Vertebrate Paleontology 25(2):370-383, June 2003.
Vickaryous, Maryanska, and Weishampel 2004. Chapter Seventeen: Ankylosauria. in The Dinosauria (2nd edition), Weishampel, D. B., Dodson, P., and Osmólska, H., editors. University of California Press.