Another alternative would be to resurrect Calipareus (Gray, 1871; type = Podiceps occipitalis) for the 'eared' group (Podiceps nigricollis, P. californicus, P. andinus, P. juninensis, P. taczanowski, P. occipitalis, P. gallordoi) - clearly separating them from Podiceps but avoiding the merge into Rollandia (which is itself not certainly monophyletic).
I'm not fully convinced using
Calipareus (which, as far as I can assess, was never used as valid at all except by Gray 1871; and Gray's use was actually an error: he attributed the name to Bonaparte, who had not made it available) is necessarily the best choice.
The situation is quite convoluted due to the fact that, for most of the 19th C., "
auritus Linn." was consistently used
sensu Latham (
1785,
1787): for Black-necked, not for Slavonian Grebe. (This is why we now have a vernacular name "Eared Grebe", which applies to
nigricollis, despite being homologous to Latin "
auritus".)
(
Colymbus auritus Linn. 1758: [
OD]
The
Fauna Svecica #123 description referenced in the OD is now thought to refer to Slavonian, and to reflect Linnaeus' concept. The other references cited in the OD are a mixed bag that is hardly of any use:
-
Aldr. orn. l. 19.
c. 52. [
here] = "
De colymbis minoribus", "About smaller grebe
s" in the plural, and which one Linnaeus meant can't be determined (most likely all at once...);
Little Grebe ("
Colymbis minor Bellonij, vel saltem simillima avis", "The smaller grebe of Bellon, or at least a very similar bird",
Black-necked Grebe? ("
Colymbi minoris aliud genus", "Another kind of smaller grebe").
-
Will. orn. 258.
t. 61. [
here] = Little Grebe.
-
Sloan. jam. 2.
p. 322.
t. 271.
f. 1. [
here],
here] = Least Grebe? (In Jamaica!)
-
Raj. av. 125. [
here] = Little Grebe.
-
Mars. danub. 82.
t. 39. [
here] = Black-necked Grebe.
-
Alb. av. 2.
p. 70.
t. 76. [
here] = Little Grebe.
-
Edw. av. 145.
t. 145.
& 96.
l. 96. [
here] & [
here] = Slavonian Grebe.)
Two generic names proposed during this period, evidently for the Black-necked Grebe (and close relatives) predate Gray's
Calipareus.
- The first one is Proctopus Kaup 1829 [OD]: originally included nominal species "Pod. auritus", no authority cited, type species by monotypy. Note the main character cited in the OD: "mit kurzem, an der Spitze in die höhe gekrümmten Schnabel" (with a short bill, curved upwards at the tip), fits Black-necked, not Slavonian. If auritus actually applies to Slavonian, the intended type species is demonstrably misidentified. This name could however never become valid, as it is preoccupied by Proctopus Fischer 1813 [OD] -- a lizard.
- The second one is Otodytes Reichenbach 1853 [OD]: introduced as a subgenus of Colymbus Briss.; made available by reference to Reichenbach's own previously published illustrations: Icones Avium, plate 11, fig. 71-73 ("Podiceps auritus (L.) LATH.", Black-necked Grebe) and 69-70 ([Podiceps] "Kallipareus LESS. GARN./occipitalis LESS.", Silvery Grebe), and plate 111, fig. 1074-75 ("Podiceps kallipareus LESS.", Silvery Grebe).
Although Reichenbach gave references to plates where names do appear, he cited no specific names in association with his subgenus in the work where he introduced it; the references do not constitute the inclusion in the genus of nominal species cited only in the referenced works (see Art. 67.2.3), thus Otodytes was made available without originally included nominal species.
The name was almost immediately placed in the synonymy of Proctopus Kaup by Gray 1855 , who cited "Colymbus auritus, Linn." as the type of the latter; this does not constitute an express inclusion of this nominal species in Otodytes either, however (see Art. 67.2.4).
The first author to have expressly included a species in Otodytes seems to be Coues 1862, who cited the name in the synonymy of Podiceps Latham, and explicitly attributed it the same type as that of Proctopus Kaup, thus "Col. auritus" (again, no authority given). It is clear from the content of this work that what Coues meant by "Col. auritus" was the European relative of what he called Podiceps (Proctopus) californicus from America, hence Black-necked and not Slavonian Grebe. If this type designation is accepted, the intended type species is again demonstrably misidentified.
After the identity of
Col. auratus Linn. was fixed, various authors associated
Podiceps nigricollis to
Proctopus/Otodytes, starting with
Gray 1871, who used
Proctopus (with
Otodytes in its synonymy) for
nigricollis, while transfering
auritus Linn. to
Dytes Kaup.
Baird, Brewer & Ridgway 1884,
Ridgway 1889,
Ogilvie-Grant 1898,
Reichenow 1900,
Scott & Sharpe 1904,
Hartert 1915,
Stuart Baker 1930, all interpreted
nigricollis as the type of
Otodytes.
Otodytes itself has been used as valid for the Black-necked Grebe, at least in the early 20th C. Japanese literature, eg.
Kuroda 1922. (
Other works in Google Books, but none is in full view.)
Art. 70.3 of the current Code allows to correct a demonstrable misidentification of the type species of a genus: under this article,
nigricollis could be designated as the type of
Otodytes, making the latter apply to the species group for which it was intended by its author. This would also preserve a name that has been used for this group in the past, rather than switching to one that, bar the OD, has no usage record at all.
Divergence time estimates in Ogawa (2015) certainly suggest that Calipareus, Rollandia & Podiceps are separate at the generic level. Whether the remaining Podiceps should be split into multiple genera is not clear. The new TiF version of Podiceps would likely need to also include Aechmophorus & Podicephorus to be monophyletic.
Based on available genetic data my
guess (but this has to remain a guess for now, as statistical support for these relationships is non-existent) would be that the remaining
Podiceps are monophyletic (if one refrains from excluding
major, which ends up sister to
cristatus in cox1 trees), thus I wouldn't change anything there.
The position of
Aechmophorus could be tested quite easily by adding data from GenBank to Ogawa et al.'s data set. (But I note that they didn't indicate anything about their data having been deposited anywhere.)
Wondering if anyone would by chance have a pdf of Bocheński 1994 to share?