Evolution of Theropod Dinosaurs

New species discoveries & the ecoevolutionary history of theropod dinosaurs

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Selected Publications

Choiniere J, Zanno LE, Balanoff A. Accepted (Invited). Basal Maniraptora. In: Makovicky PJ, Carrano M, Barrett P, and Weishampel, D. editors. The Dinosauria: Cambridge University Press.


Ksepka DT, Balanoff AM, Smith NA, Bever  GS, Bhullar B-AS, Bourdon E, Braun EL, J. Burleigh JG, Clarke JA, Colbert MW, Corfield JR, Degrange FJ, De Pietri VL, Early CM, Field  DJ, Gignac PM, Gold MEL, Kimball RT, Kawabe S, Lefebvre L, Marugán-Lobón J, Mongle CS, Morhardt A, Norell MA, Ridgely RC, Scofield RP, Tambussi CP, Torres CR, van Tuinen M, Walsh  SA, Watanabe A, Witmer LM, Wright AK, Zanno LE, Jarvis ED, Smaers JB. 2020. Tempo and pattern of avian brain size evolution. Current Biology (2020),



Canoville A, Schweitzer M, Zanno LE. 2020 (Invited). Identifying medullary bone in extinct avemetatarsalians: challenges, implications, and perspectives. Philosophical Transactions B 375: 20190133.


Woodward HN, Tremaine K, Williams SA, Zanno LE, Horner JR, Myhrvold N. 2020. Growing up Tyrannosaurus rex: osteohistology refutes the pygmy ‘Nanotyrannus’ and supports ontogenetic niche partitioning in juvenile Tyrannosaurus. Science Advances 2020; 6: eaax6250


Hedrick BP, Cordero SA, Zanno LE, Noto C, Dodson P. 2019. Quantifying shape and ecology in avian pedal claws: the relationship between the bony core and keratinous sheath. Ecology and Evolution. First published: 30 September 2019 DOI: 10.1002/ece3.5507


Canoville A, Schweitzer M, Zanno LE. 2019. Systemic distribution of medullary bone in the avian skeleton: ground truthing criteria for the identification of reproductive tissues in extinct Avemetatarsalia. BMC Evolutionary Biology 2019 19:71 DOI: 10.1186/s12862-019-1402-7


Zanno LE, Gates TA, Canoville A ,Tucker RT, Avrahami H, Makovicky PJ. 2019. Diminutive, fleet-footed tyrannosauroid narrows the 70-million-year gap in the fossil record of North American “tyrants.”  Communications Biology 2: 64 (2019)* DOI

*Altmetric Score as of 3/8/2019: 99th percentile (ranked 136th) of the 144,442 tracked articles of a similar age in all journals


Button K, Hailu Y, Kirkland JI, Zanno LE. 2017. Incremental Growth of Therizinosaurian Dental Tissues: implications for dietary transitions in Theropoda. PeerJ 5:e4129; DOI 10.7717/peerj.4129


Gates TA, Organ C, Zanno LE. 2016. Ornamentation and the rapid evolution of gigantic theropod dinosaurs. Nature Comm. 7:12931 doi:10.1038/ncomms12931 


Zanno LE, Tsogtbaatar K, Chinzorig T, Gates TA. 2016. Specializations of the Mandibular Anatomy and Dentition of Segnosaurus galbinensis (Dinosauria: Theropoda). PeerJ 4:e1885; DOI 10.7717/peerj.1885


Schweitzer MH, Zheng W, Zanno LE, Sugiyama T. 2016. Chemistry supports the identification of gender-specific reproductive tissue in Tyranosaurus rex. Scientific Reports 6, Article number: 23099 (2016) doi:10.1038/srep23099§*

§Ranked in the top 100 of 11,000 manuscripts published by Scientific Reports in 2015.

*Altmetric Score as of 3/8/2019: 99th percentile (ranked 392nd) of the 264,483 tracked articles of a similar age in all journals and 99th percentile (ranked 4th) of the 1,251 tracked articles of a similar age in Scientific Reports 


Arbour VM, Zanno LE, Larson DW, Sues H.-D. 2016. The furculae of the dromaeosaurid dinosaur Dakotaraptor steini are trionychid turtle entoplastra. PeerJ. 4:e1691

Hedrick BP, Zanno LE, Wolfe DG, Dodson P. 2015. The Slothful Claw: Osteology and Taphonomy of Nothronychus mckinleyi and N. graffami (Dinosauria: Theropoda) and Anatomical Considerations for Derived Therizinosaurids. PLoS ONE 10(6): e0129449. doi:10.1371/journal.pone.0129449


Gates TA, Zanno LE, Makovicky PJ. 2015. Theropod teeth from the upper Maastrichtian Hell Creek Formation “Sue” Quarry: new morphotypes and faunal comparisons. Acta Paleontol Pol.


Lautenschlager S, Witmer LM, Altangerel P, Zanno LE, Rayfield EJ. 2014. Cranial anatomy of Erlikosaurus andrewsi (Dinosauria: Therizinosauria): new insights based on digital reconstruction. J Vert Paleontol 34: 1263–1291.


Zanno LE, Makovicky PJ. 2013. Neovenatorid theropods are apex predators in the Late Cretaceous of North America. Nature Comm. 4:2827. doi:10.1038/ncomms3827*

*Altmetric Score as of 3/8/2019: 99th percentile (ranked 676th) of the 242,337 tracked articles of a similar age in all journals and 99th percentile (ranked 16th) of the 682 tracked articles of a similar age in Nature Communications


Zanno LE, Loewen MA, Farke AA, Kim G-S, Claessens LPAM, McGarrity CTA. 2013. Late Cretaceous theropod dinosaurs of southern Utah. In: Titus A, Loewen MA. editors. At the Top of the Grand Staircase: the Late Cretaceous of southern Utah. Bloomington: Indiana University Press. Pp. 504–525.


19. Zanno LE, Makovicky PJ. 2012. No evidence for directional evolution of body mass in herbivorous theropod dinosaurs. Proc R Soc B. 2013 280 1751 20122526; doi:10.1098/rspb.2012.2526 (published 28 November 2012) 1471-2954.


Lautenschlager S, Rayfield EJ, Altangerel P, Zanno LE, Witmer LM. 2012. The Endocranial Anatomy of Therizinosauria and its Implications for Sensory and Cognitive Function. PLOS ONE 7(12): e52289. (published 19 December 2012) doi:10.1371/journal.pone.0052289.*

*Ranked among the top 25% most cited PLOS ONE articles on record


Zanno LE, Makovicky PJ. 2011. Herbivorous ecomorphology and specialization patterns in theropod dinosaur evolution. Proc Natl Acad Sci U S A 108:232–237; published ahead of print December 20, 2010, doi:10.1073/pnas.1011924108.


Makovicky PJ, Zanno LE. 2011. Theropod diversity and the refinement of avian characteristics. In Dyke G, Kaiser G, editors. Living Dinosaurs: The Evolutionary History of Modern Birds. Berkeley: University of California Press. pp. 9–29.


Zanno LE, Varricchio DJ, O’Connor PM, Titus AL, Knell MJ. 2011. A new troodontid theropod, Talos sampsoni gen. et sp. nov., from the Upper Cretaceous Western Interior Basin of North America. PLOS ONE 6(9): e24487. doi:10.1371/journal.pone.0024487.*

*Ranked among the top 10% most cited PLOS ONE articles on record


Zanno LE, Makovicky PJ. 2011. On the earliest record of Cretaceous tyrannosauroids in western North America: implications for an Early Cretaceous Laurasian interchange event. Hist Biol 23:317–325. First published on: 24 February 2011 (iFirst), doi:10.1080/08912963.2010.543952.


Smith DK, Zanno LE, Sanders RK, Kirkland JI, DeBlieux DD. 2011. New information on the braincase of the North American therizinosaurian Falcarius utahensis. J Vertebr Paleontol 31:387–404:


Zanno LE. 2010. A taxonomic and phylogenetic re-evaluation of Therizinosauria. J Syst Palaeontol 8:503–543.


Zanno LE. 2010. Osteology of Falcarius utahensis: characterizing the anatomy of basal therizinosaurs. Zool J Linn Soc 158:196–230.


Zanno LE, Wiersma JP, Loewen MA, Sampson SD, Getty MA. 2010. Preliminary report on the theropod dinosaur fauna of the late Campanian Kaiparowits Formation, Grand Staircase-Escalante National Monument, Utah. Learning from the Land: Grand Staircase-Escalante Natl Monument Sci Symp Proc 2006 2:204–217.


Zanno LE, Gillette DD, Albright LB, Titus AL. 2009. A new North American therizinosaurid and the role of herbivory in “predatory” dinosaur evolution. Proc R Soc B 276:3505–3511.


Zanno LE. 2006. The pectoral girdle and forelimb of the primitive therizinosauroid Falcarius utahensis (Theropoda, Maniraptora): analyzing evolutionary trends within Therizinosauroidea. 2006. J Vertebr Paleontol 26:636–650.


Kirkland JI, Zanno LE, Sampson SD, Clark JM, DeBlieux DD. 2005. A primitive therizinosauroid dinosaur from the Early Cretaceous of Utah. Nature 435:84–87.


Zanno LE, Sampson SD. 2005. A new oviraptorosaur (Theropoda, Maniraptora) from the Late Cretaceous (Campanian) of Utah. J Vertebr Paleontol 25:897–904.