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Figure 6 in A new species of rorqual whale (Cetacea, Mysticeti, Balaenopteridae) from the Late Miocene of the Southern North Sea Basin and the role of the North Atlantic in the paleobiogeography of Archaebalaenoptera

Figure 6 Phylogenetic relationships within Balaenopteridae. Phylogenetic relationships of Balaenopteridae modified from Bisconti, Munsterman & Post (2019). This cladogram represents an expansion of the BALAENOPTERIDAE branch of the tree of Fig. S6. Black numbers are bootstrap support values, red numbers are symmetric resampling values. See Bisconti, Munsterman & Post (2019) for explanations of methods and discussion of the branching pattern. Full-size DOI: 10.7717/peerj.8315/fig-6

Figure 6 in A new species of rorqual whale (Cetacea, Mysticeti, Balaenopteridae) from the Late Miocene of the Southern North Sea Basin and the role of the North Atlantic in the paleobiogeography of Archaebalaenoptera

Figure 5 in A new species of rorqual whale (Cetacea, Mysticeti, Balaenopteridae) from the Late Miocene of the Southern North Sea Basin and the role of the North Atlantic in the paleobiogeography of Archaebalaenoptera

Figure 5 Left periotic and associated structures in Archaebalaenoptera liesselensis. Left periotic and associated anatomical structures. (A) Left posterolateral corner of the skull showing the periotic still in articulation. (B) Left posterolateral corner of the skull showing additional periotic characters. (C) Left posterolateral corner of the skull in lateral view showing the exposure of the posterior process of the periotic. Scale bar equals 10 cm. Photography: Michelangelo Bisconti. Full-size DOI: 10.7717/peerj.8315/fig-5

Figure 2 in A new species of rorqual whale (Cetacea, Mysticeti, Balaenopteridae) from the Late Miocene of the Southern North Sea Basin and the role of the North Atlantic in the paleobiogeography of Archaebalaenoptera

Figure 2 Holotype skull of Archaebalaenoptera liesselensis. Photographic representations of the holotype skull of Archaebalaenoptera liesselensis (OMB D2286). (A) Dorsal view. (B) Ventral view. (C) Anterolateral view. (D) Lateral view (anterior part is up). Scale bar equals 10 cm. Photography: Jaap Van Leeuwen. Full-size DOI: 10.7717/peerj.8315/fig-2

Figure 8 in A new species of rorqual whale (Cetacea, Mysticeti, Balaenopteridae) from the Late Miocene of the Southern North Sea Basin and the role of the North Atlantic in the paleobiogeography of Archaebalaenoptera

Figure 8 Paleobiogeography of Archaebalaenoptera. (A) Paleobiogeographic relationships of Archaebalaenoptera as resulting from the application of Maximum Likelihood by using MESQUITE; node letters as in Fig. 7A. (B) Phylogenetic relationships of Archaebalaenoptera species and Nehalaennia superimposed on a map of the mid-Miocene (modif. From Paleomap Project at http://www.scotese.com/miocene.htm) to show the dispersal events discussed in the text. (C) Revised paleobiogeographic patterns in Archaebalaenoptera showing unknown distributions in the branch leading to A. castriarquati; node letters as from Fig. 7A. Full-size DOI: 10.7717/peerj.8315/fig-8

Figure 7 in A new species of rorqual whale (Cetacea, Mysticeti, Balaenopteridae) from the Late Miocene of the Southern North Sea Basin and the role of the North Atlantic in the paleobiogeography of Archaebalaenoptera

Figure 7 Phylogenetic relationships and paleobiogeography of the Archaebalaenoptera clade. (A) Phylogenetic relationships of the Archaebalaenoptera clade plotted against a temporal scale to show the OTUs used for the paleobiogeographic analysis. (B) Paleobiogeographic relationships of Archaebalaenoptera as resulting from the application of Fitch's (1971) parsimony by hand; node letters as in (A). (C) Palaebiogeographic relationships of Archaebalaenoptera as resulting from the application of Maximum Parsimony by using MESQUITE; node letters as in (A). Full-size DOI: 10.7717/peerj.8315/fig-7

Figure 1 in A new species of rorqual whale (Cetacea, Mysticeti, Balaenopteridae) from the Late Miocene of the Southern North Sea Basin and the role of the North Atlantic in the paleobiogeography of Archaebalaenoptera

Figure 1 Type locality of Archaebalaenoptera liesselensis. Locality of the discovery of the holotype skull of Archaebalaenoptera liesselensis. (A) Map of The Netherlands where a red star shows the locality. (B) close-up view of the locality of the discovery near the town of Liessel. Full-size DOI: 10.7717/peerj.8315/fig-1

Figure 4 in A new species of rorqual whale (Cetacea, Mysticeti, Balaenopteridae) from the Late Miocene of the Southern North Sea Basin and the role of the North Atlantic in the paleobiogeography of Archaebalaenoptera

Figure 4 Transverse sections of the holotype skull of Archaebalaenoptera liesselensis. Transverse sections of the holotype skull of Archaebalaenoptera liesselensis. Sections 1 and 2 are done closely to the vertex and show the round transverse profile of the depression of the supraorbital process of the frontal. Sections 3, 4 and 5 are done across the temporal fossa and show the degree of overhanging of the temporal crest on the parietal. Not to scale. Photography: Jaap Van Leeuwen. Full-size DOI: 10.7717/peerj.8315/fig-4

Figure 3 in A new species of rorqual whale (Cetacea, Mysticeti, Balaenopteridae) from the Late Miocene of the Southern North Sea Basin and the role of the North Atlantic in the paleobiogeography of Archaebalaenoptera

Figure 3 Holotype skull of Archaebalaenoptera liesselensis. Interpretation of morphological characters of the holotype skull of Archaebalaenoptera liesselensis. (A) Dorsal view. (B) Ventral view. (C) Lateral view. Damaged areas are in grey. Scale bar equals 10 cm. Full-size DOI: 10.7717/peerj.8315/fig-3

opencc-zeroJun 2020View details →

Character data for taxa added to phylogenetic analyses in "A new crocodylid from the middle Miocene of Kenya and the timing of crocodylian faunal change in the late Cenozoic of Africa"

Brochuchus is a small crocodylid originally based on specimens from the early Miocene of Rusinga Island, Lake Victoria, Kenya. Here, we report occurrences of Brochuchus from several early and middle Miocene sites. Some are from the Lake Victoria region, and others are in the Lake Turkana Basin. Specimens from the middle Miocene Maboko locality form the basis of a new species, Brochuchus parvidens, which has comparatively smaller maxillary alveoli. Because of the smaller alveoli, the teeth appear to be more widely spaced in the new species. We also provide a revised diagnosis for Brochuchus and its type species, B. pigotti. A phylogenetic analysis supports a close relationship between Brochuchus and tube-snouted Euthecodon, but although relationships among crocodylids appear poorly resolved in the set of optimal trees, this is because Brochuchus and Euthecodon, along with early Miocene "Crocodylus" gariepensis from the early Miocene of Namibia, jointly adopt two distinct positions – either closely related to the living sharp-nosed crocodile (Mecistops) or to a group including the living dwarf crocodiles (Osteolaemus). Character support for a close relationship with Mecistops is problematic, and we suspect a closer relationship to Osteolaemus will be recovered with improved sampling, but the results here are ambiguous. In either case, Brochuchus is more closely related to living groups not currently found in East Africa. This material helps constrain the timing of crocodylian faunal turnover in the East African Rift Valley System, with endemic lineages largely being replaced by Crocodylus in the middle or late Miocene possibly in response to regional xerification and the replacement of continuous rainforest cover with open grasslands and savannas.

opencc-zeroJul 2020View details →

Data from: A new small, mesorostrine inioid (Cetacea, Odontoceti, Delphinida) from four late Miocene localities of the Pisco Basin, Peru

The moderately rich past diversity of the superfamily Inioidea (Cetacea, Odontoceti) in both the Atlantic and Pacific oceans contrasts with the present survival of a single genus (Inia, Amazon river dolphin, family Iniidae) in freshwater deposits of South America and of a single species (Pontoporia blainvillei, Franciscana, family Pontoporiidae) along the eastern coast of that continent. However, part of the late Miocene to Pliocene inioid fossil record is made of relatively fragmentarily known species, for which systematic affinities remain poorly understood. Based on a sample of six cranial specimens from early late Miocene (Tortonian, 9.5-8.6 Ma) marine deposits of the Pisco Formation in four localities of the East Pisco Basin (southern coast of Peru), we describe a new genus and species of inioid, Samaydelphis chacaltanae. Bearing a proportionally short rostrum with an upper tooth count of about 30 teeth per row, this small-sized species is characterized by a moderately elevated vertex of the cranium displaying a long anteromedial projection of the frontals and interparietal, as well as by the plesiomorphic retention of a premaxilla-nasal contact. Recovered as a member of the family Pontoporiidae in our phylogenetic analysis, S. chacaltanae falls as sister-group to Meherrinia isoni, from the late Miocene of North Carolina (U.S.A.), which has previously been tentatively referred to the Iniidae or regarded as a stem Inioidea. Originating from the P1 allomember of the Pisco Formation, the mesorostrine S. chacaltanae was contemporaneous and sympatric with two other inioids, the brevirostrine pontoporiid Brachydelphis mazeasi and the longirostrine iniid Brujadelphis ankylorostris.

opencc-zeroDec 2020View details →

Data from: Nasal compartmentalization in Kogiidae (Cetacea, Physeteroidea): Insights from a new late Miocene dwarf sperm whale from the Pisco Formation

Facial compartmentalization in the skull of extant pygmy whales (Kogiidae) is a unique feature among cetaceans that allows the housing of a wide array of organs responsible for echolocation. Recent fossil findings depict a remarkable disparity of the facial bone organization in Miocene kogiids, but the significance of such a rearrangement for the evolution of the clade has been barely explored. Here we describe Kogia danomurai sp. nov., a late Miocene (ca. 5.8 Ma) taxon from the Pisco Formation (Peru), based on a partially preserved skull with a new facial bone pattern. Our phylogenetic analysis recovers K. danomurai as the most basal representative of the extant genus Kogia, displaying a combination of derived (incipiently developed and excavated sagittal facial crest) and plesiomorphic features (high position of the temporal fossa and antorbital notch not transformed into a narrow slit). Furthermore, when compared with the extant Kogia, the facial patterning found in K. danomurai indicates differential development among the facial organs, implying different capabilities of sound production relative to extant Kogia spp. Different facial bone patterns are particularly notable within the multi-species kogiid assemblage of the Pisco Formation, which suggests causal connections between different patterns and feeding ecologies (e.g., nekton piscivory and benthic foraging). At about 5.8 Ma, K. danomurai was part of a cetacean community composed by clades typical of the late Miocene as well as other early representatives of extant taxa, a mixture probably depicting the initial faunal change toward the coastal ecosystem dynamics of the present-day Southeastern Pacific.

opencc-zeroDec 2016View details →

Data from: Carnivoran resource and habitat use in the context of a Late Miocene faunal turnover episode

We investigate resource and habitat use by apex predators through stable isotope analysis at two Spanish Late Miocene localities: Los Valles de Fuentidueña (~9.6 Ma, LVF) and Cerro de los Batallones (~9.1 Ma, BAT). The temporal window represented by LVF and BAT was crucial in the shaping of the current Iberian mammalian structure because it corresponds to the initial stages of a faunal turnover episode and regional environmental change at ~9.5–8.5 Ma (Vallesian–Turolian transition), associated with an increase in the seasonality of precipitation. Herbivore and carnivore δ13C and δ18O values do not point to significant changes in either the vegetation cover (a woodland to mesic C3 grassland) or the hydrological regime during the time lapse represented between LVF and BAT. This suggests that the environmental shift recorded around the Vallesian–Turolian boundary may have occurred later in time, since LVF and BAT ages are synchronic with the onset of the turnover event. From the standpoint of predator–prey evaluation by means of stable isotope analysis, statistical post hoc tests, mixing model output, and the assessment of niche occupation by LVF and BAT carnivores point to high levels of interspecific competition among large active carnivores, albeit some genera, such as the amphicyonid Magericyon and specially the hyaenid Lycyaena, seemed to avoid competition by taking prey from a more open habitat. Despite the drop in diversity and change in faunal components observed between the LVF and BAT assemblages, a high degree of resource and habitat competition is evident from stable isotope data.

opencc-zeroDec 2014View details →

Data from: No deep diving: evidence of predation on epipelagic fish for a stem beaked whale from the late Miocene of Peru

Although modern beaked whales (Ziphiidae) are known to be highly specialized toothed whales that predominantly feed at great depths upon benthic and benthopelagic prey, only limited palaeontological data document this major ecological shift. We report on a ziphiid–fish assemblage from the Late Miocene of Peru that we interpret as the first direct evidence of a predator–prey relationship between a ziphiid and epipelagic fish. Preserved in a dolomite concretion, a skeleton of the stem ziphiid Messapicetus gregarius was discovered together with numerous skeletons of a clupeiform fish closely related to the epipelagic extant Pacific sardine (Sardinops sagax). Based on the position of fish individuals along the head and chest regions of the ziphiid, the lack of digestion marks on fish remains and the homogeneous size of individuals, we propose that this assemblage results from the death of the whale (possibly via toxin poisoning) shortly after the capture of prey from a single school. Together with morphological data and the frequent discovery of fossil crown ziphiids in deep-sea deposits, this exceptional record supports the hypothesis that only more derived ziphiids were regular deep divers and that the extinction of epipelagic forms may coincide with the radiation of true dolphins.

opencc-zeroDec 2015View details →

Data from: A systematic review of cetothere baleen whales (Cetacea, Cetotheriidae) from the Late Miocene of Crimea and Caucasus, with a new genus

Nine taxa of Miocene baleen whales were described from the Black Sea region under the name Cetotherium before 1951, and a further four closely related species representing three genera have been added in recent years. This rich diversity requires taxonomic revision and ordering. Here, a new genus, Mithridatocetus, is described from the Tortonian of Crimea and Caucasus, with two species, M. eichwaldi and M. adygeicus (originally Kurdalagonus adygeicus); 'Cetotherium' mayeri (a nomen dubium) is also a member of this genus. In comparison with other Cetotheriinae, Mithridatocetus is distinguished by the autapomorphic shape of the tympanic bulla with the swollen main ridge, the lowered anterior portion of the involucrum and the oblique anterolateral margin; such synapomorphies, as a transversely narrow squamosal with the ventromedially oriented postglenoid process (shared with Eucetotherium), a squamosal cleft (shared with Kurdalagonus) and an oval surface of the compound posterior process of the tympanoperiotic on the posterolateral skull wall (shared with Brandtocetus); and a unique combination of a high neurocranium and a long and robust paroccipital process. The genus Kurdalagonus is redefined here as containing only one described species, K. mchedlidzei. Therefore, the group Cetotheriinae is now restricted to the latest Serravallian and Tortonian of the Eastern Paratethys and includes at least five genera: Cetotherium, Brandtocetus, Kurdalagonus, Mithridatocetus and Zygiocetus. In addition, ?Cetotherium priscum and C. incertum are considered to be nomina dubia; 'Cetotherium' klinderi and 'Cetotherium' pusillum require more complete specimens for reassessment; 'Cetotherium' maicopicum and Eucetotherium helmersenii require further research to identify their taxonomical affinities.

opencc-zeroDec 2019View details →

To mate, or not to mate: the evolution of reproductive diapause facilitates insect radiation into African savannahs in the Late Miocene

1. Many tropical environments experience cyclical seasonal changes, frequently with pronounced wet and dry seasons, leading to a highly uneven temporal distribution of resources. Short-lived animals inhabiting such environments often show season-specific adaptations to cope with alternating selection pressures. 2. African Bicyclus butterflies show strong seasonal polyphenism in a suite of phenotypic and life-history traits, and their adults are thought to undergo reproductive diapause associated with the lack of available larval host plants during the dry season. 3. Using three years of longitudinal field data for three species in Malawi, dissections demonstrated that one forest species reproduces continuously whereas two savannah species undergo reproductive diapause in the dry season, either with or without pre-diapause mating. Using additional data from field-collected and museum samples, we then documented the same three mating strategies for a further 37 species. 4. Phylogenetic analyses indicated that the ancestral state was a non-diapausing forest species, and that habitat preference and mating strategy evolved in a correlated fashion. 5. Bicyclus butterflies underwent rapid diversification during the Late Miocene, coinciding with expansions into more open savannah habitat. We conclude that the ability to undergo reproductive diapause was a key trait that facilitated colonization and eventual radiation into savannahs in the Late Miocene.