Solving a long-standing nomenclatorial controversy: designation of a neotype for the southern sea lion Otaria flavescens (Shaw, 1800)
Author
Lucero, Sergio
Author
Rodríguez, Sara M.
Author
Teta, Pablo
Author
Cassini, Guillermo
Author
D’Elía, Guillermo
text
Zootaxa
2019
2019-02-13
4555
2
296
300
journal article
27550
10.11646/zootaxa.4555.2.13
3607ad60-33c1-4aee-81b4-1034b289182a
1175-5326
2624283
657CC088-0A8F-456F-B899-63234AB1C7AF
Otaria flavescens
(Shaw, 1800)
Synonyms
:
aurita
Bechstein, 1800;
byronia
de
Blainville, 1820
;
chilensis
Muller, 1841;
chonotica
Philippi, 1892;
fulva
Philippi, 1892;
godeffroyi
Peters, 1866;
hookeri
Schlater, 1866;
leoninus
F.G. Cuvier, 1827;
minor
Gray, 1874;
molossina
Lesson and Garnot, 1826;
mollosinus
Lesson, 1827;
pernettyi
Lesson, 1827;
pygmaea
Gray, 1874;
rufa
Philippi, 1892;
ulloae
Tschudi, 1844;
uraniae
Lesson, 1827;
velutina
Philippi, 1892.
Neotype
.
MACN-Ma 23.26,
Adult
male, skull and mandible, almost without teeth, acquired by the
Museo Argentino de Ciencias Naturales
“Bernardino Rivadavia” on
july 18th, 1923
(data on collector is missing) (
Fig. 2
).
Type locality.
San Sebastián (ca. -53.2979, -68.4512), Provincia de Tierra del Fuego,
Antártida
e Islas del Atlántico Sur,
República Argentina
(
Fig. 3
).
Measurements of the
neotype
.-
Condylobasal length =
346.4 mm
; zygomatic width = 236.0 mm; braincase width =
120.5 mm
; rostral length =
88.3 mm
; rostral width = 100.0 mm; rostral height =
76.1 mm
; postorbital constriction =
33.8 mm
; mastoid width = 210.0; palatal length = 206.0 mm; palatal width = 55.0 mm; upper postcanine length = 94.0 mm; alveolus width of upper canine = 24.0 mm; length of dentary =
276.4 mm
; coronoid height = 120.0; length of coronoid process = 89.0 mm; length of lower postcanine row = 81.0 mm;
Distribution.
Otaria flavescens
is distributed along the Atlantic and Pacific coasts, from the
Galápagos Islands
in
Ecuador
(Pacific) and southern
Brazil
(Atlantic) in the north, to the archipelago of Tierra del Fuego and
Islas Malvinas
in the south (
Aguayo and Maturana, 1973
;
Pine
et al
., 1978
; Sielfeld, 1983;
Bastida
et al
., 2007
).
FIGURE 1.
Male (in front) and female (behind) of
Otaria flavescens
(Shaw, 1800)
from Monte León, Santa Cruz, Argentina (Ph: S. Lucero).
Emended morphological diagnosis.
(modified from
Brunner, 2003
) A species of the family
Otariidae
characterized by the following combination of character states: skull robust; rostrum sloped and broad, specially between the canines; nasals short and broad; preorbital processes well developed; interorbital constriction wide; supraorbital processes robust, rounded-to-quadrate; palate long, reaching the hamular process of the pterygoid, and wide, with its lateral edges curved ventrally; posterior border of the palate nearly straight; zygomatic arches wide, planned dorsoventrally at the squamoso- jugular margin; mastoids heavy and long in adult males but more reduced in females; canines large and robust; sagittal crest most pronounced in adult males, extending along the frontal and increasing in height towards the occipital crest; occipital crest in males very robust, flaring dorsolaterally from the posterior margins of the sagittal crest; mandible heavy, particularly at the canine roots; coronoid process with a deep and long masseteric fossa (see
Fig. 2
).
Remarks:
Usage of the name
flavescens
has some advantages in searches for bibliography and occurrence records over the usage of
byronia
. For example, a search in Google Scholar (https://scholar.google.com/; conducted on
November 11, 2018
) for
Otaria flavescens
retrieved 3550 results against 1800 for
Otaria byronia
. Similarly, there are 3704 documented occurrences for
Otaria byronia
in GBIF (Global Biodiversity Information Facility; accessed on
November 11, 2018
) against 552 for
O. byronia
.
FIGURE 2.
Neotype of
Phoca flavescens
Shaw, 1800
(MACN-Ma 23.26). Scale = 50mm.
FIGURE 3.
Map of southern South America, depicting the restricted type locality (red star) of
Phoca flavescens
Shaw, 1800
(MACN- Ma 23.26). The blue shadow in the inset South American map indicates the distributional range of
Otaria flavescens
.
The type locality of
Phoca byronia
was defined as “…the island of
Tinian
…Cette île est l’une des îles Marianiies ou des Larrons, située à l’est des Phillipines ou par le 15° de latitude méridionale et le 215° de long. méridionale de Greenwich” (de
Blainville, 1820
) (=
Northern Mariana Islands
in the northeastern Pacific); however, as have been discussed by several authors (e.g.,
Rodriguez & Bastida, 1993
), this is likely an error, since this island is far away from the known distribution of this species and of any other otarid. Scheffer (1958), based on the discussion provided by
Allen (1905)
and
Hamilton (1934)
, stated that the
holotype
of
byronia
probably came from the Strait of Magellan or Islas Juan Fernandez. This is a large area that encompasses both Atlantic and mostly Pacific waters, between
33.90° S
,
80.70° W
and
52.60° S-
68.30 ° W
. With the evidence at hand, it is not possible to determine the exact provenance of the animal studied by de Blainville. Considering the uncertainty on the geographic origin of the type of
byronia
and given that it is lost (
Rodríguez and Bastida, 1993
), the selection of a
neotype
for this taxon is also warranted; this action would allow ending the ambiguity on to which populations this taxonomic form applies. Having said that, we prefer to not undertake this nomenclatorial action and leave it for a future taxonomic study aimed to test the putative distinction between Peruvian and northern Chilean populations and Atlantic and southern Chilean populations, to which currently the taxonomic name
flavescens
applies.
We end this contribution mentioning the well-known fact that even for well-studied and charismatic large mammals, as the pinnipeds, nomenclatorial and taxonomic issues are still pending of resolution. As such, we call for continuing support of collection-based research aimed to characterize the biodiversity at the species level.