BURHINIDAE, Mathews, 1912

Smith, A, 2015, Sixteen vetted fossil calibrations for divergence dating of Charadriiformes (Aves, Neognathae), Palaeontologia Electronica 18 (1), pp. 1-18 : 6

CLADE BURHINIDAE

Node Calibrated (3): Burhinidae (stone curlews). Divergence of Burhinidae (i.e., Burhinus and Esacus ) from Chionis (sheathbills) and Pluvianellus socialis (Magellanic Plover; Figure 1 )

Fossil Taxon. Genucrassum bransatensis De Pietri and Scofield, 2013

Specimen. NMB Cod. 1258 ( Natural History Museum Basel , Switzerland) holotype specimen of Genucrassum bransatensis , carpometacarpus .

Phylogenetic Justification. NMB Cod. 1258 was referred to Burhinidae by De Pietri and Scofield (2013) based on apomorphies of the carpometacarpus. The following apomorphies that support referral of NMB Cod. 1258 were cited by De Pietri and Scofield (2013): (1) strongly developed and ventrally projecting processus extensorius; (2) caudally well-developed ventral portion of trochlea carpalis, displaying a sharp angle distally. No alternative hypothesis has been proposed linking this specimen to any clade other than Burhinidae .

Minimum Age. Oligocene-Miocene boundary (Chattian-Aquatanian boundary) 23.03 Ma

Soft Maximum Age. Not specified

Age Justification. The Codret Quarry (Coderet- Bransat), from which the holotype of Genucrassum bransatensis was collected, is the reference locality for the Paleogene mammalian zone MP30. Zone MP30 is considered to bracket the Miocene-Oligocene boundary with an age estimated between 24.1-23.6 Ma ( Hugueney et al., 2003). The age of the boundary between the Oligocene and Miocene has been revised to 23.03 Ma ( International Commission on Stratigraphy, 2012.) and is recommended herein as a constraint on the divergence between Burhinidae and other Charadrii.

Discussion. The fossil record of Burhinidae , and the early fossil record of Charadrii in general, is quite sparse ( Mayr, 2009; De Pietri and Scofield, 2013). The next oldest record of Burhinidae is Burhinus lucorum from the early Miocene of North America ( Bickart, 1981). Results of molecular sequence-based phylogenetic analyses (e.g., Baker et al., 2007; Figure 1 ) place Burhinidae as the sister taxon to a clade consisting of the Sheathbills (i.e., Burhinus and Esacus ) and the monotypic genus Pluvianellus (i.e., Magellanic Plover P. socialis ). In contrast, a recent morphology-based phylogenetic analysis recovered Burhinidae as the sister taxon to the monotypic plover genus Pluvianus (i.e., Egyptian Plover P. aegyptius ; Mayr, 2011). If Burhinidae is the sister taxon to Pluvianus , rather than the sister taxon to Pluvianellus as represented herein, then Genucrassum bransatensis would provide a calibration for the basal divergence of crown Charadrii.

Figures

FIGURE 1. Phylogram of charadriiform relationships showing calibrated nodes 1-7 (modified from Baker et al., 2007, figure 1). Numbered nodes in red correspond to the following calibrations: (1) divergence of Charadriiformes from its nearest outgroup; (2) divergence of Charadrii from other Charadriiformes; (3) divergence of Burhinidae from Chionis and Pluvianellus; (4) divergence of Jacanidae from other Scolopaci; (5) basal divergence among Calidridinae; (6) divergence of Turnicidae from Lari; (7) basal divergence of Laromorphae; (8) divergence of Alcidae from Stercorariidae.