In the late 1970s eight Balaenoptera specimens of unknown identity were caught in the lower latitudinal Indo-Pacific waters by Japanese research whaling vessels1. The combination of the allozyme patterns and physical maturity of the eight specimens separated them from all acknowledged Balaenoptera species2. In September 1998 we collected a medium-sized baleen whale carcass on a coastal island in the Sea of Japan. This specimen and the previously collected eight specimens resembled Balaenoptera physalus (fin whale) in external appearance but were much smaller. Comparison of external morphology, osteology and mitochondrial DNA data grouped the nine specimens as a single species but separated them from all known baleen whale species. Therefore, here we describe a new species of Balaenoptera, which is characterized by its unique cranial morphology, its small number of baleen plates, and by its distant molecular relationships with all of its congeners. Our analyses also separated Balaenoptera brydei (Bryde's whale)3,4 and Balaenoptera edeni (Eden's whale)5 into two distinct species, raising the number of known living Balaenoptera species to eight.

A newly discovered species of living baleen whale

Balaenopteroids (Balaenopteridae + Eschrichtiidae) are a diverse lineage of living mysticetes, with seven to ten species divided between three genera (Megaptera, Balaenoptera and Eschrichtius). Extant members of the Balaenopteridae (Balaenoptera and Megaptera) are characterized by their engulfment feeding behavior, which is associated with a number of unique cranial, mandibular, and soft anatomical characters. The Eschrichtiidae employ suction feeding, which is associated with arched rostra and short, coarse baleen. The recognition of these and other characters in fossil balaenopteroids, when viewed in a phylogenetic framework, provides a means for assessing the evolutionary history of this clade, including its origin and diversification. The earliest fossil balaenopterids include incomplete crania from the early late Miocene (7‐10 Ma) of the North Pacific Ocean Basin. Our preliminary phylogenetic results indicate that the basal taxon, “Megaptera” miocaena should be reassigned to a new genus based on its possession of primitive and derived characters. The late late Miocene (5‐7 Ma) balaenopterid record, except for Parabalaenoptera baulinensis and Balaenoptera siberi, is largely undescribed and consists of fossil specimens from the North and South Pacific and North Atlantic Ocean basins. The Pliocene record (2‐5 Ma) is very diverse and consists of numerous named, but problematic, taxa from Italy and Belgium, as well as unnamed taxa from the North and South Pacific and eastern North Atlantic Ocean basins. For the most part Pliocene balaenopteroids represent extinct species and genera and reveal a greater degree of morphological diversity than at present. The Pleistocene record is very limited and, unfortunately, fails to document the evolutionary details leading to modern balaenopteroid species diversity. It is evident, however, that most extant species evolved during the Pleistocene. Morphological and molecular based phylogenies support two competing hypotheses concerning relationships within the Balaenopteroidea: (1) balaenopterids and eschrichtiids as sister taxa, and (2) eschrichtiids nested within a paraphyletic Balaenopteridae. The addition of fossil taxa (including a new Pliocene species preserving a mosaic of balaenopterid and eschrichtiid characters) in morphological and “total evidence” analyses, offers the potential to resolve the current controversy concerning the possible paraphyly of Balaenopteridae.

http://www.bio.sdsu.edu/faculty/BERTA_files/Demere%20et%20al_2005.pdf

The Taxonomic and Evolutionary History of Fossil and Modern Balaenopteroid Mysticetes

A review of available catch and biological data suggests that there are 3 populations of Bryde's whales in the southern African region. An inshore population (the South African Inshore Stock) occurs over the continental shelf of South Africa, south of about 30° S, and seems to be non- migratory, although there is a movement up the west coast in winter. A pelagic population (the South- east Atlantic Stock) occurs on the west coast of southern Africa, ranging from equatorial regions to about 34° S, and appears to migrate north in autumn and south in spring. Whales from the Southeast Atlantic Stock differ from the South African Inshore Stock in size, scarring, baleen shape, seasonality of reproduction, fecundity and prey types. Both occurred in the west coast whaling ground off Donkergat, but with differing seasonalities and distributions from the coast. Bryde's whales are rare on the east coast of southern Africa, but are found in summer in some numbers south of Madagascar. Whales from this population are clearly smaller than those from the Southeast Atlantic Stock, but are similar in size to, or even smaller than, those from the South African Inshore Stock. Their external appearance is unknown, but they differ in prey type from the South African Inshore Stock, and because of a clear discontinuity in distribution it is believed that they form a third (pelagic) popula- tion (the Southwest Indian Ocean Stock). This population may or may not move north as far as the Seychelles in winter, but seems to be separate from Bryde's whales in the Arabian Sea. From their size composition, length at sexual maturity and infrequent capture, Bryde's whales taken at Durban may have represented strays from either the South African Inshore Stock or the Southwest Indian Ocean Stock, and recorded stomach contents also indicate prey types common to either stock. The unusual degree of population differentiation shown by Bryde's whales may be a consequence of their limited seasonal migrations and apparent resource partitioning.

/pdf/distribution-and-population-separation-of-bryde-s-whale-4l5d0wzxef.pdf

Distribution and population separation of Bryde's whale Balaenoptera edeni off southern Africa

Balaenoptera omurai is a newly discovered baleen whale that represents an ancient evolutionary lineage

Background 
Anatomical comparisons of the ear region of baleen whales (Mysticeti) are provided through detailed osteological descriptions and high-resolution photographs of the petrotympanic complex (tympanic bulla and petrosal bone) of all extant species of mysticete cetaceans. Salient morphological features are illustrated and identified, including overall shape of the bulla, size of the conical process of the bulla, morphology of the promontorium, and the size and shape of the anterior process of the petrosal. We place our comparative osteological observations into a phylogenetic context in order to initiate an exploration into petrotympanic evolution within Mysticeti.


Principal Findings 
The morphology of the petrotympanic complex is diagnostic for individual species of baleen whale (e.g., sigmoid and conical processes positioned at midline of bulla in Balaenoptera musculus; confluence of fenestra cochleae and perilymphatic foramen in Eschrichtius robustus), and several mysticete clades are united by derived characteristics. Balaenids and neobalaenids share derived features of the bulla, such as a rhomboid shape and a reduced anterior lobe (swelling) in ventral aspect, and eschrichtiids share derived morphologies of the petrosal with balaenopterids, including loss of a medial promontory groove and dorsomedial elongation of the promontorium. Monophyly of Balaenoidea (Balaenidae and Neobalaenidae) and Balaenopteroidea (Balaenopteridae and Eschrichtiidae) was recovered in phylogenetic analyses utilizing data exclusively from the petrotympanic complex.


Significance 
This study fills a major gap in our knowledge of the complex structures of the mysticete petrotympanic complex, which is an important anatomical region for the interpretation of the evolutionary history of mammals. In addition, we introduce a novel body of phylogenetically informative characters from the ear region of mysticetes. Our detailed anatomical descriptions, illustrations, and comparisons provide valuable data for current and future studies on the phylogenetic relationships, evolution, and auditory physiology of mysticetes and other cetaceans throughout Earth's history.

/pdf/the-comparative-osteology-of-the-petrotympanic-complex-ear-1jns72x9gj.pdf

The Comparative Osteology of the Petrotympanic Complex (Ear Region) of Extant Baleen Whales (Cetacea: Mysticeti)

A Fin Whale was cast ashore on the coast of Pulu Sugi, one of the smaller islands of the Rhio Archipelago between Singapore and the Sumatran coast in July 1936. Thanks to the generosity of Dr. K. W. Dammerman, former Director of 's Lands Plantentuin at Buitenzorg, and the unvaluable help of the late Mr. F. N. Chasen, Director of the Raffles Museum, Singapore, the specimen was saved and after cleaning sent to the Rijksmuseum van Natuurlijke Historie, Leiden. It was received in June 1939.
The length of the skeleton was slightly over 12 m and it must have belonged to an adult specimen, for in all vertebrae the epiphyses are coalesced completely with the rest of the vertebral body (Wheeler, 1930). It was clear that the specimen belonged to a Balaenoptera. It was too large for a B. acutorostrata and too small for a B. physalus and nearly related to B. borealis, but there were some important characters in which it differed from this species. The preliminary examination showed that especially the flat rostrum, the form of the part of the skull between the palatine bones and the occipital condyles were markedly different and also that the form of the atlas and the backward direction of the spinous processes of the dorsal and lumbar vertebrae did not agree with borealis. All these characters pointed to B. edeni, a species from the Indian region still insufficiently known, and also to B. brydei, though the latter was only known from South African waters. The stranding of the Pulu Sugi Whale offered a good opportunity to make a close comparison of edeni and brydei and if possible to clear up the relation between these two species. B. edeni was described by Anderson (1878), who gave a description of the skeleton from a specimen stranded in Thyabu Choung off the Gulf of Martaban. B. brydei was

/pdf/on-a-specimen-of-the-rare-fin-whale-balaenoptera-edeni-2gsv0qx1w4.pdf

G.C.A. Junge

Papers

On a specimen of the rare fin whale, Balaenoptera Edeni Anderson, stranded on Pulu Sugi near Singapore