Kairuku waewaeroa sp. nov. (1 Viewer)

[Fred Ruhe]

Simone Giovanardi, Daniel T. Ksepka & Daniel B. Thomas, 2021

A giant Oligocene fossil penguin from the North Island of New Zealand

Journal of Vertebrate Paleontology. Online edition: e1953047. doi:10.1080/02724634.2021.1953047

Abstract: https://www.tandfonline.com/doi/abs/10.1080/02724634.2021.1953047?journalCode=ujvp20

Penguins (Sphenisciformes) have arguably the most complete and continuous fossil record of any avian clade, offering an ever-improving understanding of penguin phylogeny, biogeography, and the evolution of wing-propelled diving. Yet, our knowledge of the precise body proportions of stem-group penguins remains poor due to a dearth of articulated specimens. Here, we describe Kairuku waewaeroa sp. nov., a new giant penguin species from the Glen Massey Formation (Whaingaroan stage, 34.6–27.3 Ma). The holotype skeleton, discovered in Kawhia Harbour, North Island, New Zealand, is one of the most complete skeletons of a giant penguin yet uncovered. Our phylogenetic analysis recovers a clade uniting the New Zealand endemics Kairuku waewaeroa, Kairuku waitaki, and Kairuku grebneffi, which is supported by synapomorphies including a stout femoral shaft and tibiotarsi with a distinctly convex medial condyle. Kairuku waewaeroa is unique among stem penguins in having elongate tibiotarsi, revealing a new long-legged stem penguin body plan. The discovery of Kairuku waewaeroa contributes yet another penguin species to an Oligocene avifauna for Zealandia that is replete with giant birds.

Enjoy,

Fred

 

[ornithociencia]

Hi Fred. Do you have the figures of this paper?

 

[Fred Ruhe]

Hi Fred. Do you have the figures of this paper?

Yes, I have and will put them on Birdforum soon.

Fred

 

[Fred Ruhe]

SYSTEMATIC PALEONTOLOGY

AVES Linnaeus, 1758
SPHENISCIFORMES Sharpe, 1891
SPHENISCIDAE Bonaparte, 1831
KAIRUKU Ksepka, Fordyce, Ando, and Jones, 2012.

Type Species —Kairuku waitaki Ksepka, Fordyce, Ando and Jones, 2012.

Differential Diagnosis — Three apomorphies distinguish Kairuku from other penguin genera: (1) stout femur (midshaft width equals 14.5–15.7% femur length in undeformed specimens), (2) tibiotarsus with distinctly convex medial border in distal view, and (3) absence of crista medialis hypotarsi. The presence of two sternal articular facets on the coracoid is a potential additional apomorphy, but the distribution of this character remains poorly known for stem group penguins. Species of Kairuku can be further differentiated from Pachydyptes ponderosus and Icadyptes salasi (for which leg bones remain unknown) by a more slender humerus, from Palaeeudyptes by the relatively straight humerus shaft (more sigmoid in Palaeeudyptes) and from Kaiika (for which only the humerus is known) by straighter (versus sigmoid) humerus shaft and more narrow fossa for insertion of m. pectoralis.

KAIRUKU WAEWAEROA sp. nov.

Holotype—Specimen WM 2006/1/1, two cervical vertebra, four thoracic vertebrae, at least seven ribs, synsacrum, partial left ischium, partial sternum, left coracoid, partial right scapula, left and right humerus, radius and ulna, right ulnare, left carpometacarpus, left manual phalanx II-1, left and right femur and tibiotarsus, pedal phalanx III-1, pedal ungual

Etymology—From Te reo Māori, waewae (“legs”) and roa (“long”) referencing the elongate hindlimbs.

Type Locality and Age—Small peninsula along the eastern margin of Kawhia Harbour, near TeWaitere in theWaikato District of the North Island of New Zealand (Fig. 1). Glen Massey Formation, Whaingaroan local stage (34.6–27.3 Ma).

Differential Diagnosis—Distinguished from Kairuku waitaki and Kairuku grebneffi by larger size, presence of a deep ovoid fossa on the ventral face of the processus acrocoracoideus of the coracoid, and finger-like shape of the processus lateralis of the coracoid. Further differentiated from Kairuku grebneffi by the rounded (versus squared) shape of the olecranon.

Fred


FIGURE 1. Kairuku waewaeroa sp. nov. from the Glen Massey Formation of New Zealand, holotype (WM 2006/1/1). A, line drawing of specimen. B, photo of the specimen WM 2006/1/1 with most bones in ventral view. Contrast adjusted for readability. C, skeletal and size comparison of Kairuku waewaeroa sp. nov. (WM 2006/1/1) and Emperor Penguin, Aptenodytes forsteri. Abbreviations: cv, cervical vertebrae; cor, coracoid; cmc, carpometacarpus; fem, femur; hum, humerus; mpII-1, manual phalanx II-1; pb, pubis; ppIII-1, pedal phalanx III-1; pu, pedal ungueal; rd, radius; sc, scapula; ster, sternum; syns, synsacrum; tbt, tibiotarsus; u, ulnare; ul, ulna; tv, thoracic vertebrae.

FIGURE 2. Agreement subtree from parsimony analysis of the penguin matrix. Bold regions of branches identify time ranges from stratigraphic dating, including stratigraphic uncertainty. Node labels represent bootstrap values >50. Life-reconstructions represent key fossil taxa from New Zealand along with some extant species. A, Sequiwaimanu osieae; B, Platydyptes novaezealandiae; C, Eudyptes atatu; D, Kairuku waewaeroa sp. nov. (WM 2006/1/1); E, Eudyptes chrysocome; F, Spheniscus magellanicus; G, Pygoscelys adeliae; H, Aptenodytes patagonicus.