Bimbisula melanodactylos gen. et sp. nov. (1 Viewer)

Richard D. Benson & Bruce R. Erickson, 2013

A New Genus and Species of Booby (Sulidae: AVES) From the Pliocene of South Carolina, with a New Corollary to the Nature of Sister Taxa

The Science Museum of Minnesota Monographs in Paleontology 7: 46 pg.

Free pdf: https://www.smm.org/sites/default/files/public/attachments/new-genus-species-of-booby.pdf

Abstract:

A new genus and species of booby is described from the Goose Creek Limestone (middle Blancan) of South Carolina. Based on a partial skeleton of one individual and the referred cranium of another, the new taxon, a gannet-booby mosaic, resembles gannets (Morus: Morini) as much as boobies (Sula and Papasula: Sulini) by count of characters. Although devoid of unambiguous autapomorphies of its own, the new taxon is an unlikely ancestor to modern boobies, as it is more primitive than Sula guano Brodkorb, a somewhat earlier (early Pliocene) species. The known antiquity of the sulid family (early Oligocene) is probably of greater age than that of the most recent common ancestor of gannets and boobies (subfamily Sulinae), on the evidence of both molecular distance and the morphology of the earliest (and certain Miocene) sulids. Therefore some fossil sulids should be placed in at least one extinct subfamily rather than in modern genera. Although sulid fossils throughout the Miocene have been assigned to Sula, we find little evidence that Sula is that ancient. The new genus here described indicates a greater sulin generic diversity, in which Sula is a relatively young genus most closely related to other sulin (but gannetlike) taxa. Several paleogenera have been placed in the gannet clade. Whether the extant genus Morus is a relatively young or a persistent old genus among these paleogenera, a ghost lineage connects the seemingly younger Sulini with its sister group, the Morini. If it is true that sister taxa are of equal age, then the unknown members of the ghost lineage of the apparently younger sister taxon are expected to closely resemble, and be confusable with, the members of the other sister taxon, as the earliest sulins are expected to be confusable with morins. Similar examples from other groups in the fossil record are given.

The paper describes Bimbisula melanodactylos gen. et sp. nov.

Enjoy,

Fred

Systematic Paleontology

Class Aves
Order Pelecaniformes
Suborder Sulae
Family Sulidae
Bimbisula melanodactylos gen. et sp. nov.

Etymology. Genus name: “Dawn Booby”, from Bimbi, Gullah personal name, from Fula (Nigerian and West African lingua franca) bimbi (“dawn”). The Gullah name has reference to the South Carolinian locality of the type specimens, and avoids the overly-used element Eo- (from Greek Eos, “Dawn”). Traditionally, sulid generic names have reference to the “foolish” lack of fear in these birds to human predation (Icelandic sula = Greek moros = English booby = “fool”). Not part of this tradition, Bimbisula does not intentionally resemble the word “bimbo” or the word “imbecile”. The gender of Bimbisula, like that of Sula, is feminine.
Species epithet: Greek for “black-fingered”, by analogy with the Homeric expression rhododactylos Eos (“rosy-fingered Dawn”, Odyssey 5.121, 23.241). The Black-fingered Dawn Booby’s name has reference to the black color of the iron-darkened type specimens, which do include a
finger bone, and also pays homage to another sulid species, Sula dactylatra, whose name also seems to signify “black-fingered”. Bimbisula melanodactylos, like other sulids, may have had black primaries. Like rhododactylos, melanodactylos is a common-gender adjective (masculine and feminine).

Holotype. Charleston Museum PV2818, partial skeleton of a single individual including the rostrum, left and right mandibular fragments, furcular end of left coracoid, sternal end of right coracoid, symphyseal fragment of furcula, anterior ends of both scapulae, fragmentary sternum, proximal end of left humerus, mostly complete right manual phalanx II:1, fragmentary right vertebral rib, fragmentary synsacrum, complete right femur, proximal end of right tibiotarsus, and complete right tarsometatarsus;
collected by James Malcom, 1980.

Referred specimen. Science Museum of Minnesota P90.38.8, cranium collected by B. R. Erickson, 27 October 1990.

Horizon. Middle Pliocene, middle Blancan. Holotype: Goose Creek Limestone, upper unit; absolute age: 3.6-3.5 Ma. Referred cranium: Goose Creek Limestone, unit unknown; absolute age: 3.9-3.8 or 3.6-3.5 Ma.

Locality. South Carolina, Charleston County. Holotype: Seaboard Railroad Locality: north ditch along Seaboard Coast Line Railway, 1.0 mi (1.6 km) W of Dorchester Road overpass. Referred cranium: Wando Terminal Site.

Fred