scholarly journals A new Miocene baleen whale from the Peruvian desert

2016 ◽  
Vol 3 (10) ◽  
pp. 160542 ◽  
Author(s):  
Felix G. Marx ◽  
Naoki Kohno
Keyword(s):  
Soft Tissue ◽  
Late Miocene ◽  
Feeding Strategy ◽  
Stomach Contents ◽  
Baleen Whale ◽  
Baleen Whales ◽  
Southern Peru ◽  
Pisco Formation ◽  
Stark Contrast ◽  
Lunge Feeding

The Pisco-Ica and Sacaco basins of southern Peru are renowned for their abundance of exceptionally preserved fossil cetaceans, several of which retain traces of soft tissue and occasionally even stomach contents. Previous work has mostly focused on odontocetes, with baleen whales currently being restricted to just three described taxa. Here, we report a new Late Miocene rorqual (family Balaenopteridae), Incakujira anillodefuego gen. et sp. nov., based on two exceptionally preserved specimens from the Pisco Formation exposed at Aguada de Lomas, Sacaco Basin, southern Peru. Incakujira overall closely resembles modern balaenopterids, but stands out for its unusually gracile ascending process of the maxilla, as well as a markedly twisted postglenoid process of the squamosal. The latter likely impeded lateral (omega) rotation of the mandible, in stark contrast with the highly flexible craniomandibular joint of extant lunge-feeding rorquals. Overall, Incakujira expands the still meagre Miocene record of balaenopterids and reveals a previously underappreciated degree of complexity in the evolution of their iconic lunge-feeding strategy.

scholarly journals A new genus and species of eomysticetid (Cetacea: Mysticeti) and a reinterpretation of ‘Mauicetus’ lophocephalus Marples, 1956: transitional baleen whales from the upper Oligocene of New Zealand

2018 ◽  
Author(s):  
Robert Boessenecker ◽  
R. Ewan Fordyce
Keyword(s):  
Phylogenetic Analysis ◽  
New Zealand ◽  
Temporomandibular Joint ◽  
New Genus ◽  
Feeding Strategy ◽  
Thoracic Vertebrae ◽  
New Genus And Species ◽  
Baleen Whales ◽  
Upper Oligocene ◽  
Lunge Feeding

The early evolution of toothless baleen whales (Chaeomysticeti) remains elusive despite a robust record of Eocene-Oligocene archaeocetes and toothed mysticetes. Eomysticetids, a group of archaic longirostrine and putatively toothless baleen whales fill in a crucial morphological gap between well-known toothed mysticetes and more crownward Neogene Mysticeti. A historically important but perplexing cetacean is “Mauicetus” lophocephalus (upper Oligocene South Island, New Zealand). The discovery of new skulls and skeletons of eomysticetids from the Oligocene Kokoamu Greensand and Otekaike Limestone permit a redescription and modern reinterpretation of “Mauicetus” lophocephalus, and indicating that this species may have retained adult teeth. A new genus and species, Tokarahia kauaeroa, is erected on the basis of a well-preserved subadult to adult skull with mandibles, tympanoperiotics, and cervical and thoracic vertebrae, ribs, sternum, and forelimbs from the Otekaike Limestone (>25.2 Ma). “Mauicetus” lophocephalus is relatively similar and recombined as Tokarahia lophocephalus. Phylogenetic analysis supports inclusion of Tokarahia within the Eomysticetidae alongside Eomysticetus, Micromysticetus, Yamatocetus, and Tohoraata, and strongly supports monophyly of Eomysticetidae. Tokarahia lacked extreme rostral kinesis of extant Mysticeti and primitively retained a delicate archaeocete-like posterior mandible and synovial temporomandibular joint, suggesting that Tokarahia was capable of at most, limited lunge feeding in contrast to extant Balaenopteridae, and utilized an alternative as-yet unspecified feeding strategy.

scholarly journals Intraformational unconformities as a record of late Miocene eustatic falls of sea level in the Pisco Formation (southern Peru)

2018 ◽  
Vol 14 (2) ◽  
pp. 607-619 ◽  
Author(s):  
Claudio Di Celma ◽  
Elisa Malinverno ◽  
Giulia Bosio ◽  
Karen Gariboldi ◽  
Alberto Collareta ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Miocene ◽  
Southern Peru ◽  
Pisco Formation

scholarly journals A new Miocene baleen whale from Peru deciphers the dawn of cetotheriids

2017 ◽  
Vol 4 (9) ◽  
pp. 170560 ◽  
Author(s):  
Felix G. Marx ◽  
Olivier Lambert ◽  
Christian de Muizon
Keyword(s):  
Cranial Morphology ◽  
Baleen Whale ◽  
Baleen Whales ◽  
Pisco Formation ◽  
Distinctive Morphology ◽  
Form Part ◽  
New Material ◽  
Characteristic Features ◽  
Distinct Morphology ◽  
A New Species

Cetotheriidae are an iconic, nearly extinct family of baleen whales (Mysticeti) with a highly distinct cranial morphology. Their origins remain a mystery, with even the most archaic species showing a variety of characteristic features. Here, we describe a new species of archaic cetotheriid, Tiucetus rosae , from the Miocene of Peru. The new material represents the first mysticete from the poorly explored lowest portion of the highly fossiliferous Pisco Formation (allomember P0), and appears to form part of a more archaic assemblage than observed at the well-known localities of Cerro Colorado, Cerro los Quesos, Sud-Sacaco and Aguada de Lomas. Tiucetus resembles basal plicogulans (crown Mysticeti excluding right whales), such as Diorocetus and Parietobalaena , but shares with cetotheriids a distinct morphology of the auditory region, including the presence of an enlarged paroccipital concavity. The distinctive morphology of Tiucetus firmly places Cetotheriidae in the context of the poorly understood ‘cetotheres’ sensu lato , and helps to resolve basal relationships within crown Mysticeti.

Diet and feeding strategy of thornback ray, Raja clavata (Chondrichthyes: Rajidae) from the Gulf of Gabes (Tunisia—Central Mediterranean Sea)

2014 ◽  
Vol 94 (7) ◽  
pp. 1509-1516 ◽  
Author(s):  
Hasna Kadri ◽  
Sondes Marouani ◽  
Mohamed Nejmeddine Bradai ◽  
Abderrahmen Bouaïn
Keyword(s):  
Feeding Strategy ◽  
Stomach Contents ◽  
Ontogenetic Changes ◽  
Central Mediterranean ◽  
Gulf Of Gabes ◽  
Gulf Of Gabès ◽  
Thornback Ray ◽  
Raja Clavata ◽  
Food And Feeding ◽  
Quantitative Analyses

Food and feeding strategy of the thornback ray, Raja clavata, were studied from stomach contents analysis of specimens caught monthly in the Gulf of Gabes. The data were analysed according to sex, size and season. At total of 1280 stomachs was examined, from specimens ranging from 14 to 110 cm total length (TL), of which 1076 (83.98%) contained food. Thornback ray feed mainly on teleosts, crustaceans and cephalopods, whereas gastropods and polychaetes are occasionally consumed. Significant differences were found between the diets of males and females; however, ontogenetic changes were also detected, with crustaceans constituting the greatest proportion of the diet of smaller rays. Both teleosts and cephalopods increased in importance with growth of the skates. Prey diversity increased with size; large and mobile prey species were more commonly found in the diet of larger skates. Diet composition showed seasonal variations. Quantitative analyses and graphical methods indicate that the thornback ray is a generalist feeder.

Ontogenetic shifts in natural diet, chelae, and mandible of an omnivorous freshwater crab (Aegla uruguayana): linking morphology and function

2021 ◽  
Author(s):  
Maria Florencia Viozzi ◽  
Juan Manuel Cabrera ◽  
Federico Giri ◽  
Debora de Azevedo Carvalho ◽  
Verónica Williner
Keyword(s):  
Morphological Changes ◽  
Feeding Strategy ◽  
Stomach Contents ◽  
Trophic Niche ◽  
Composition Analysis ◽  
Diet Change ◽  
Geometric Morphometric ◽  
Natural Diet ◽  
Plant Remains ◽  
And Function

We analyze whether ontogenetic diet change in Aegla uruguayana (Schmitt, 1942) is related to the morphological changes in chelae and mandibles. We use a combination of scanning electron microscope observation (SEM), dietary composition analysis (stomach observation, trophic niche amplitude, trophic overlap, and feeding strategy), and geometric morphometric tools (discriminant analysis and two-block partial least squares analysis). The two structures analyzed by SEM show differences between juvenile and adult specimens, both in their cuticle and morphology specializations. In juveniles, the absence of the lobular tooth is the notable feature. However, in adult sizes it is marked development. Both groups have simple setae with infracuticular articulation and denticles with different arrangements between groups. In the incisive mandible process, the teeth and spines present sharper points in juveniles and considerable wear in adults. Aegla uruguayana presented two trophic strategies: a profile of more predatory traits when younger and mostly detritivorous when adults. The analysis of geometric morphometry substantiates the patterns observed in SEM and stomach contents analysis. The morphology of smaller specimens is associated with the consumption of animal items (ephemeropterans larvae and cladocerans), while in those of larger sizes; it is related to the consumption of plant remains.

scholarly journals Stratigraphic framework of the late Miocene Pisco Formation at Cerro Los Quesos (Ica Desert, Peru)

2015 ◽  
Vol 12 (5) ◽  
pp. 1020-1028 ◽  
Author(s):  
C. Di Celma ◽  
E. Malinverno ◽  
G. Cantalamessa ◽  
A. Gioncada ◽  
G. Bosio ◽  
...  
Keyword(s):  
Late Miocene ◽  
Pisco Formation ◽  
Stratigraphic Framework

scholarly journals Salishicetus meadi , a new aetiocetid from the late Oligocene of Washington State and implications for feeding transitions in early mysticete evolution

2018 ◽  
Vol 5 (4) ◽  
pp. 172336 ◽  
Author(s):  
Carlos Mauricio Peredo ◽  
Nicholas D. Pyenson
Keyword(s):  
North Pacific ◽  
Fossil Record ◽  
Feeding Strategy ◽  
Washington State ◽  
Late Oligocene ◽  
Baleen Whales ◽  
The North ◽  
Occlusal Wear ◽  
Basal Clade ◽  
The North Pacific

Living baleen whales, or Mysticeti, lack teeth and instead feed using keratinous baleen plates to sieve prey-laden water. This feeding strategy is profoundly different from that of their toothed ancestors, which processed prey using the differentiated dentition characteristic of mammals. The fossil record of mysticetes reveals stem members that include extinct taxa with dentition, illuminating the morphological states that preceded the loss of teeth and the subsequent origin of baleen. The relationships among stem mysticetes, including putative clades such as Mammalodontidae and Aetiocetidae, remain debatable. Aetiocetids are among the more species-rich clade of stem mysticetes, and known only from fossil localities along the North Pacific coastline. Here, we report a new aetiocetid, Salishicetus meadi gen. et sp. nov, from the late Oligocene of Washington State, USA. Salishicetus preserves a near-complete lower dentition with extensive occlusal wear, indicating that it processed prey using shearing cheek teeth in the same way as its stem cetacean ancestors. Using a matrix with all known species of aetiocetids, we recover a monophyletic Aetiocetidae, crownward of a basal clade of Mammalodontidae. The description of Salishicetus resolves phylogenetic relationships among aetiocetids, which provides a basis for reconstructing ancestral feeding morphology along the stem leading to crown Mysticeti.

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