Thursday, October 15, 2015

[PaleoOrnithology • 2015] Hakawai melvillei • Wading A Lost Southern Connection: Miocene Fossils from New Zealand Reveal A New Lineage of Shorebirds (Charadriiformes) Linking Gondwanan Avifaunas

Hakawai melvillei
De Pietri, Scofield, Tennyson, Hand & Worthy, 2015  

An endemic and previously unknown lineage of shorebirds (Charadriiformes: Scolopaci) is described from early Miocene (19–16 Ma) deposits of New Zealand. Hakawai melvillei gen. et sp. nov. represents the first pre-Quaternary record of the clade in New Zealand and offers the earliest evidence of Australasian breeding for any member of the Scolopaci. Hakawai melvillei was a representative of the clade that comprises the South American seedsnipes (Thinocoridae) and the Australian Plains-wanderer (Pedionomidae), and presumed derived features of its postcranial skeleton indicate a sister taxon relationship to Australian pedionomids. Our findings reinforce that terrestrial adaptations in seedsnipes and the Plains-wanderer are convergent as previously proposed, and support an ancestral wading ecology for the clade. Although vicariance events may have contributed to the split between pedionomids and H. melvillei, the proposed sister taxon relationship between these taxa indicates that the split of this lineage from thinocorids must have occurred independently from Australia and Zealandia's separation from the rest of Gondwana.

Keywords: Scolopaci, Pedionomidae, Miocene, fossil birds, St Bathans Fauna

Systematic palaeontology
Class Aves Linnaeus, 1758
Order Charadriiformes Huxley, 1867
Suborder Scolopaci Strauch, 1978 sensu Paton et al. (2003)

Family incertae sedis 

Genus Hakawai gen. nov. 
Type species. Hakawai melvillei sp. nov. 

Derivation of name. The generic name refers to an unseen and enigmatic ‘mystery bird’ in Maori mythology; gender is feminine. Although recent research shows that Maori from Rakiura (Stewart Island) considered the Coenocorypha snipe’s nocturnal aerial calls to be those of the Hakawai (Miskelly 1987), our choice alludes to a link between the mythical Hakawai and waders of the suborder Scolopaci. The specific name honours NZ-based ornithologist and ecologist David Melville, for his efforts in implementing conservation measures for shorebirds, locally and globally

Figure 4. Proposed Gondwanan diversification of the lineage from which the South American seedsnipes (Thinocoridae), the Australian Plains-wanderer (Pedionomidae) and the New Zealand (NZ) Hakawai melvillei gen. et sp. nov. originated. Continents are shown in their current position but the splits are likely to have taken place before 40 Ma (see main text). The possibility of trans-Tasman dispersal between Australia and NZ is indicated by a dotted arrow and a question mark. However, there is no evidence of a common ancestor of H. mellvillei and pedionomids in Australia, and Oligocene pedionomids already shared derived traits with Pedionomus torquatus (De Pietri et al. 2015) that are absent in H. melvillei. We propose instead that both lineages have common ancestry in East Gondwana before its final fragmentation, and became independently isolated following complete separation of NZ and Australia from the rest of Gondwana. Insets: A, phylogeny of Scolopaci (Gibson & Baker 2012), showing the proposed sister taxon relationship between H. melvillei and pedionomids; B, position of continents at 55 Ma (Lawver & Gahagan 2003). Bird images reproduced with permission of HBW Alive (Baker-Gabb 1996; Fjeldsa 1996).

Vanesa L. De Pietri, R. Paul Scofield, Alan J. D. Tennyson, Suzanne J. Hand and Trevor H. Worthy. 2015. Wading A Lost Southern Connection: Miocene Fossils from New Zealand Reveal A New Lineage of Shorebirds (Charadriiformes) Linking Gondwanan Avifaunas. Journal of Systematic Palaeontology.   DOI: 10.1080/14772019.2015.1087064

New Zealand fossils reveal new bird species @physorg_com
A new species of shorebird, dating from a time when New Zealand was covered in subtropical forests and crocodiles roamed parts of the South Island, has been found near St Bathans in Central Otago.