  Citation: Tennyson, A.J.D.; Greer, L.; Lubbe, P.; Marx, F.G.; Richards,M.D.; Giovanardi, S.; Rawlence, N.J. A New Species of Large Duck (Aves: Anatidae) from the Miocene of New Zealand. Taxonomy 2022, 2, 136–144. https://doi.org/10.3390/ taxonomy2010011 Academic Editor: Mathias Harzhauser Received: 16 February 2022 Accepted: 7 March 2022 Published: 9 March 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Article A New Species of Large Duck (Aves: Anatidae) from the Miocene of New Zealand † Alan J. D. Tennyson 1, * , Liam Greer 2 , Pascale Lubbe 3 , Felix G. Marx 1,4 , Marcus D. Richards 4 , Simone Giovanardi 5 and Nicolas J. Rawlence 2 1 Museum of New Zealand Te Papa Tongarewa, Wellington 6011, New Zealand; felix.marx@tepapa.govt.nz 2 Otago Palaeogenetics Laboratory, Department of Zoology, University of Otago, Dunedin 9010, New Zealand; pwlgreer@gmail.com (L.G.); nic.rawlence@otago.ac.nz (N.J.R.) 3 Department of Anatomy, University of Otago, Dunedin 9016, New Zealand; pl.lubbe@gmail.com 4 Department of Geology, University of Otago, Dunedin 9016, New Zealand; arcadiafrica@gmail.com 5 School of Natural and Computational Sciences, Massey University, Auckland 0632, New Zealand; giovanerd90@gmail.com * Correspondence: alant@tepapa.govt.nz † urn:lsid:zoobank.org:pub:E7FFF522-08CD-4B1B-9D8A-3247556655D0. Abstract: We describe a new species of extinct duck, Miotadorna catrionae sp. nov. (Anatidae, Tadornini, Tadorninae), based on a right humerus from the Miocene lacustrine deposits of St Bathans, Otago, New Zealand. Principal component analysis reveals that the new taxon is distinguished by its large size and relative proportions. This is the eighth and largest species of duck described from the St Bathans fossil assemblage and further underscores the global importance of this site for understanding anatid evolution. Keywords: Tadornini; Miotadorna catrionae sp. nov.; fossil; shelduck; lacustrine; Bannockburn Formation 1. Introduction In the St (Saint) Bathans area of Central Otago, New Zealand, outcrops of the Bannock- burn Formation, a late early–earliest middle Miocene lacustrine sequence, include a rich fossil biota from the ancient Lake Manuherikia [1–3]. The deposits have yielded the most diverse terrestrial vertebrate assemblage described from pre-Pleistocene Zealandia: numer- ous fish [4] and water birds, as well as rarer land birds, bats, lizards, frogs, crocodilians, a rhynchocephalian, a turtle and other mammal remains of uncertain affinity [2]. St Bathans is one of the richest localities for Miocene anatids worldwide, with seven species described to date [2]. Two geese may also have been present but remains thus far have been too fragmentary to allow their formal description [5]. Here, we describe a large anatid humerus and demonstrate that it represents a new species of large duck. 2. Material and Methods Until now, most of the large anatid fossils from the St Bathans area were referred to the extinct shelduck Miotadorna sanctibathansi Worthy, Tennyson, Jones, McNamara and Douglas, 2007 [6], while a few bones were referred to undescribed forms of geese [5,6]. We tested the hypothesis that all the large anatid humeri from this fossil assemblage represent one species. This was conducted by assessing morphological variation, using both morphometrics and anatomy. We measured all large anatid humeri (those about the size of M. sanctibathansi) from the St Bathans assemblage housed at the Museum of New Zealand Te Papa Tongarewa (Wellington, New Zealand; NMNZ) and one specimen at the Geology Museum, Department of Geology, University of Otago (Dunedin, New Zealand; OU) that preserve at least one of the following: total length, proximal width, proximal depth, shaft width, distal width Taxonomy 2022, 2, 136–144. https://doi.org/10.3390/taxonomy2010011 https://www.mdpi.com/journal/taxonomy