Measurements of NMV P221273.

<p>Measurements of NMV P221273.</p

NMV P221273, left humerus.

<p>A, Ventral; B, dorsal; C, distal, D, caudal; and E, proximal views. Abbreviations: ahh, apex of humeral head; ccs, coracobrachialis caudalis scar; cd, condylus dorsalis; cv, condylus ventralis; dtr, dorsal trochlear ridge; fp, fossa pneumotricipitalis; hh, humeral head; hp, humeral plexus; ic, incisura capitis; iims, impressio insertii musculi supracoracoideus; imdm, impressio musculi deltoideus minor; imld, impressio musculi latissimus dorsi; imp, impressio musculi pectoralis; pa, preaxial angle; sfp, secondary fossa pneumotricipitalis; sh, shelf adjacent to condylus ventralis; sst, sulcus scapulotricipitalis; st, sulcus transversus; td, tuberculum dorsale; tv, tuberculum ventrale. Scale bars represent 10 mm. Specimen whitened with ammonium chloride.</p

Locality map and stratigraphical section.

<p><b>(A)</b> Maps showing the localities of penguin fossils NMV P221273, NMV P232062 and NMV P251637, plus measured stratigraphic sections (Port 1–4) at Portland, Victoria, Australia. <b>(B)</b> The stratigraphy of the Portland outcrop. The vertical scale is in metres, the coordinates of each section are: Port 1, 38°20′14″S, 141°36′35″E; Port 2, 38°20′29″S, 141°36′27″E; Port 3, 38°20′18″S, 141°36′32″E; Port 4, 38°20′04″S, 141°36′33″E. The occurrence of <i>Gr</i>. <i>conomiozea</i> in Port 2 is from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153915#pone.0153915.ref027" target="_blank">27</a>]. Coarser cross-bedded calcarenite units are indicated. The blue arrows are microfossil samples, the purple arrows are brachiopods samples for Sr analyses. <b>(C)</b> Sr ages of brachiopods (see also Tables <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153915#pone.0153915.t001" target="_blank">1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153915#pone.0153915.t002" target="_blank">2</a>). Results of replicate analyses of the seven brachiopods from the horizon denoted (4mBRACH) at log level 4 metres are in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153915#pone.0153915.t001" target="_blank">Table 1</a>. The black circle and red line are the preferred ages with +/- error; the surrounding grey box shows the total age range of each sample. The green shading is the most likely age range of the outcrop; the light blue incorporates the full error of the Sr dates. <b>(D)</b> The bio-chronostratigraphy of the Mio-Pliocene [after 35] showing the most likely age of the vertebrate fossils from the Port Campbell Limestone at Portland. Abbreviations: km, kilometres; m, metres; Ma, million years ago; Port, geological section; Sr, strontium.</p

Synthesis of Australian penguin evolution.

<p>Stratigraphically-calibrated phylogeny of Sphenisciformes correlated with tectonic movements and changing ocean circulation in the southern hemisphere showing how: (1) the Australian taxa are dispersed across the phylogeny temporally; (2) the Australian continent becomes progressively more isolated from other southern continents; and (3) a strengthened ACC (indicated by the black arrows) provides a new dispersal vector to Australia despite the presence of a strengthening Antarctic Polar Front (APF). The bottom palaeomaps are based on reconstructions in Lawver & Gahagan [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153915#pone.0153915.ref009" target="_blank">9</a>]. Penguin silhouettes show overall trend for decreasing body size in penguin evolution: Top, archaic giant stem penguin taxa; middle medium-sized stem penguin taxa; bottom, smaller crown penguin taxa (silhouette credit: Fir0002/Flagstaffotos (original photo), John E. McCormack, Michael G. Harvey, Brant C. Faircloth, Nicholas G. Crawford, Travis C. Glenn, Robb T. Brumfield & T. Michael Keesey, used under a CC BY 3.0 Attribution Unported Licence (<a href="http://creativecommons.org/licenses/by/3.0/" target="_blank">http://creativecommons.org/licenses/by/3.0/</a>))). Palaeoceanographic reconstructions after [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153915#pone.0153915.ref009" target="_blank">9</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153915#pone.0153915.ref072" target="_blank">72</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153915#pone.0153915.ref074" target="_blank">74</a>]. Palaeoceanographic abbreviations: EAC = East Australian Current, pEAC = palaeo-East Australian Current, pRG = palaeo-Ross Sea Gyre/Tasman Current, RG = Ross Sea Gyre. The relative strength of the ACC and APF is shown by thickening arrows and lines though time. Black arrow = cold currents, red arrows = warm currents.</p

Phylogeny of Sphenisciformes including Australian OTUs.

<p>Strict consensus of: A, 194 most parsimonious trees with an unconstrained search; and B, 219 most parsimonious trees with crown Sphenisciformes constrained (denoted by the yellow star) in a constrained search. Standard bootstrap (1000 replicates) absolute frequency values are in bold above their respective nodes and symmetric resampling (1000 replicates) frequency difference values are in regular font below their respective nodes. Best score reached was 5377 for both phylogenies.</p

Replicate analyses of two batches of brachiopods from the 4mBRACH and Port 1, P1-1.15 m horizons.

<p>The standard error (s.e.) uncertainty is calculated using Student's t test as outlined in [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153915#pone.0153915.ref033" target="_blank">33</a>].</p

Referred material.

<p>NMV P251637, partial right humerus in: A, dorsal; and B, ventral views.</p

The age of the brachiopods at Portland.

<p>The age of the brachiopods at Portland.</p

New Miocene Fossils and the History of Penguins in Australia

<div><p>Australia has a fossil record of penguins reaching back to the Eocene, yet today is inhabited by just one breeding species, the little penguin <i>Eudyptula minor</i>. The description of recently collected penguin fossils from the re-dated upper Miocene Port Campbell Limestone of Portland (Victoria), in addition to reanalysis of previously described material, has allowed the Cenozoic history of penguins in Australia to be placed into a global context for the first time. Australian pre-Quaternary fossil penguins represent stem taxa phylogenetically disparate from each other and <i>E</i>. <i>minor</i>, implying multiple dispersals and extinctions. Late Eocene penguins from Australia are closest to contemporaneous taxa in Antarctica, New Zealand and South America. Given current material, the Miocene Australian fossil penguin fauna is apparently unique in harbouring ‘giant penguins’ after they went extinct elsewhere; and including stem taxa until at least 6 Ma, by which time crown penguins dominated elsewhere in the southern hemisphere. Separation of Australia from Antarctica during the Palaeogene, and its subsequent drift north, appears to have been a major event in Australian penguin biogeography. Increasing isolation through the Cenozoic may have limited penguin dispersal to Australia from outside the Australasian region, until intensification of the eastwards-flowing Antarctic Circumpolar Current in the mid-Miocene established a potential new dispersal vector to Australia.</p></div