A night heron (Ciconiiformes, Ardeidae) and a stork (Ciconiidae) from the Pliocene of Myanmar (Burma)

Abstract

Two new avian specimens from the Pliocene part of the Irrawaddy sediments of central Myanmar represent the youngest known fossil records of birds from Myanmar (Burma) that previously was restricted to one specimen of an ibis from the middle Eocene. The age of the Sulegon-1 fossil locality is likely from the later part of the Pliocene based on the presence of the suid Sivachoerus prior, the anthracotheriid Merycopotamus dissimilis, and the Sumatran rhinoceros Dicerorhinus sp. cf. D. sumatrensis. The distal tarsometatarsus is from a night heron (Ardeidae: Nycticoracini) and exhibits derived (and primitive) features consistent with night herons, but not other groups of ardeids, including the absence of a lateral deflection of trochlea III and a trochlear furrow extending to the proximal plantar end of trochlea III. The night heron fossil is not distinguishable from some species of Gorsachius and Nycticorax and may derive from one of the extant species in Southeast Asia. The other specimen (a distal tibiotarsus) represents a taxon of stork (Ciconiidae: cf. Leptoptilini) and displays many characters associated with that group (incuding a large centrally positioned intercondylar tubercle, a rounded intercondylar fossa, and distally notched trochlear rims). This stork is smaller than the 'giant' storks known from the Plio-Pleistocene of Asia and Africa, and may represent a relative of one of the large extant Asian storks. The inferred paleohabitat of the Sulegon locality as a tidal deltaic habitat is consistent with the lifestyle of both the extant night herons and large storks that occur in southeastern Asia today.

Short Note Were ibises (Aves, Threskiornithidae) present in Antarctica?

“…The fossil record of ibises is largely incomplete and very patchy. In this sense, the early record of ibises remains poorly documented, being represented by an isolated tibiotarsus from the Eocene of Myanmar (Stidham et al 2016), and the enigmatic genus Rynchaeites from the Middle Eocene of Germany and Denmark (Mayr & Bertelli 2011).…”

The first darter (Aves: Anhingidae) fossils from India (late Pliocene)

“…The fossil record of birds in India now includes several Eocene taxa (e.g., [ 3 ]), the Neogene taxa from the Siwaliks Hills (e.g., [ 1 , 4 ]), and some Pleistocene material (e.g., [ 5 ]). Overall, the known past diversity of birds in India is not rich, and the fossil record of birds across southern Asia is generally poorly known (e.g., [ 4 , 6 , 7 ]). Neogene fossils of birds from India and neighboring Pakistan include pelicans, storks, ostriches, and other terrestrial and aquatic taxa [ 1 , 2 , 4 , 8 ].…”