A new pliocene dolphin (Cetacea: Pontoporiidae), from the Lee Creek Mine, North Carolina

Gibson, Matthew L.; Geisler, Jonathan H.

doi:10.1671/039.029.0307

Cited by 18 publications

(19 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“… Geisler et al (2011) used a combined morphological and molecular analysis to clarify the relationships among extant and fossil lineages of cetaceans, with mostly a focus on odontocetes, including some important fossil taxa, but taxon sampling within Inioidea was relatively sparse compared to Geisler, Godfrey & Lambert (2012) . This latter work, which described Meherinnia isoni Geisler, Godfrey & Lambert, 2012 , a late Miocene inioid from marine rocks of North Carolina, USA, also included other fossil inioids such as Auroracetus bakerae Gibson & Geisler, 2009 , Ischyrorhynchus vanbenedeni Ameghino, 1891 , Protophocaena minima , and Stenasodelphis russellae Godfrey & Barnes, 2008 , some of which were not included in subsequent phylogenetic analyses of odontocetes, such as the one by Murakami et al (2014) . The starting point for our analysis was the matrix provided by Aguirre-Fernández & Fordyce (2014) in their description of the early Miocene stem odontocete Papahu taitapu Aguirre-Fernández & Fordyce, 2014 , which used the morphological partition of Geisler, Godfrey & Lambert (2012) in their description of Meherrinia , along with some important modifications (e.g., the removal of Mysticeti and unpublished specimens, and coding revisions for select stem odontocetes) that enhanced its utility for resolving fossil and living odontocete relationships.…”

Section: Methodsmentioning

confidence: 99%

“…1 ). Fossil pontoporiids have been described from shallow marine and estuarine strata of early late Miocene to Early Pliocene age from the Atlantic coast of North America, including Maryland, Virginia, North Carolina and Florida ( Morgan, 1994 ; Whitmore, 1994 ; Godfrey & Barnes, 2008 ; Gibson & Geisler, 2009 ; Geisler, Godfrey & Lambert, 2012 ). Along the Atlantic coast of Europe, Protophocaena minima Abel, 1905 from shallow marine Miocene of the Netherlands, is now recognized as a pontoporiid ( Lambert & Post, 2005 ) based on additional cranial and periotic material from the Miocene of Belgium and the Netherlands.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Isthminia panamensis, a new fossil inioid (Mammalia, Cetacea) from the Chagres Formation of Panama and the evolution of ‘river dolphins’ in the Americas

Pyenson

Vélez‐Juarbe

Gutstein

et al. 2015

PeerJ

View full text Add to dashboard Cite

In contrast to dominant mode of ecological transition in the evolution of marine mammals, different lineages of toothed whales (Odontoceti) have repeatedly invaded freshwater ecosystems during the Cenozoic era. The so-called ‘river dolphins’ are now recognized as independent lineages that converged on similar morphological specializations (e.g., longirostry). In South America, the two endemic ‘river dolphin’ lineages form a clade (Inioidea), with closely related fossil inioids from marine rock units in the South Pacific and North Atlantic oceans. Here we describe a new genus and species of fossil inioid, Isthminia panamensis, gen. et sp. nov. from the late Miocene of Panama. The type and only known specimen consists of a partial skull, mandibles, isolated teeth, a right scapula, and carpal elements recovered from the Piña Facies of the Chagres Formation, along the Caribbean coast of Panama. Sedimentological and associated fauna from the Piña Facies point to fully marine conditions with high planktonic productivity about 6.1–5.8 million years ago (Messinian), pre-dating the final closure of the Isthmus of Panama. Along with ecomorphological data, we propose that Isthminia was primarily a marine inhabitant, similar to modern oceanic delphinoids. Phylogenetic analysis of fossil and living inioids, including new codings for Ischyrorhynchus, an enigmatic taxon from the late Miocene of Argentina, places Isthminia as the sister taxon to Inia, in a broader clade that includes Ischyrorhynchus and Meherrinia, a North American fossil inioid. This phylogenetic hypothesis complicates the possible scenarios for the freshwater invasion of the Amazon River system by stem relatives of Inia, but it remains consistent with a broader marine ancestry for Inioidea. Based on the fossil record of this group, along with Isthminia, we propose that a marine ancestor of Inia invaded Amazonia during late Miocene eustatic sea-level highs.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Isthminia panamensis, a new fossil inioid (Mammalia, Cetacea) from the Chagres Formation of Panama and the evolution of ‘river dolphins’ in the Americas

Pyenson

Vélez‐Juarbe

Gutstein

et al. 2015

PeerJ

View full text Add to dashboard Cite

show abstract

“…While some extinct and extant freshwater species are recorded among Iniidae ( Cozzuol, 2010 ; Gutstein, Cozzuol & Pyenson, 2014 ), all inioids attributed to the family Pontoporiidae are reported from marine environments. To date the following pontoporiid genera are recognised: the extinct Auroracetus , Brachydelphis , Pliopontos , Pontistes , Protophocaena , and Stenasodelphis , and the extant Pontoporia , ( Burmeister, 1885 ; Muizon, 1984 ; Muizon, 1988b ; Lambert & Post, 2005 ; Godfrey & Barnes, 2008 ; Gibson & Geisler, 2009 ; Lambert & Muizon, 2013 ). The anatomy of Pontoporia blainvillei , from the coastal waters of eastern South America is known in detail ( Flower, 1867 ; Brownell Jr, 1989 ), and cranial and some postcranial remains of Brachydelphis and Pliopontos , from the southeast Pacific, are also well described.…”

Section: Introductionmentioning

confidence: 99%

Scaldiporia vandokkumi, a new pontoporiid (Mammalia, Cetacea, Odontoceti) from the Late Miocene to earliest Pliocene of the Westerschelde estuary (The Netherlands)

Post

Louwye

Lambert

2017

PeerJ

View full text Add to dashboard Cite

BackgroundThe family Pontoporiidae (Cetacea, Odontoceti, Inioidea) is currently represented in our oceans by just one species of diminutive dolphin (Pontoporia blainvillei, franciscana). Although P. blainvillei is limited to coastal waters of the South Atlantic along Brazil, Uruguay and Argentina, multiple Miocene and Pliocene fossils indicate the past presence of members of the family in the South Atlantic, South Paciifc and North Atlantic oceans. Our comprehension of the origin and diversity of this clade and of the relationships of its members with other inioids is hampered by the fact that part of the described fossil specimens, especially from the North Atlantic realm, are cranial fragments often associated to limited stratigraphic information.MethodsBased on an almost complete fossil cranium of pontoporiid from the Westerschelde estuary, The Netherlands, whose preservation allows for detailed morphological observations, we describe a new genus and species. The latter is compared to other pontoporiids, as well as a few non-pontoporiid inioids. A phylogenetic analysis is performed to investigate the relationship of S. vandokkumi with the best-known extinct and extant inioids. Palynological analysis of the sediment associated to the holotype is used to assess its geological age.Results and discussionThe new genus and species Scaldiporia vandokkumi is characterized among others by greatly thickened premaxillary eminences reaching the level of the antorbital notch. Palynologically dated from the late Tortonian—earliest Zanclean (7.6–5 Ma, Late Miocene—earliest Pliocene), this new pontoporiid confirms the surprising past diversity of marine inioids in the North Atlantic area. Finally the content of the pontoporiid subfamily Brachydelphininae is briefly discussed.

show abstract

“…However, Inia and Pontoporia , two endemic and exclusively South American genera that are sister taxa (forming the clade Inioidea sensu Muizon ), possess a comparatively rich fossil record (Fordyce and Barnes, ; Fordyce et al, ; Messenger and McGuire, ; Cozzuol, ). Fossil pontoporiids have been identified in Neogene marine deposits in both the Southern and Northern hemispheres (Muizon, , ; Lambert and Post, ; Pyenson and Hoch, ; Godfrey and Barnes, ; Gibson and Geisler, ; Gutstein et al, ; Lambert and Muizon, ). Fossil Iniidae, by contrast, appear restricted mostly to South America, with work by Cozzuol (, , ), Muizon (, ), Cozzuol and da Silva (), recognizing three fossil genera in South America (Fig.…”

Section: Introductionmentioning

confidence: 99%

The Antiquity of Riverine Adaptations in Iniidae (Cetacea, Odontoceti) Documented by a Humerus from the Late Miocene of the Ituzaingó Formation, Argentina

Cozzuol

Pyenson

2014

The Anatomical Record

View full text Add to dashboard Cite

"River dolphins" are a paraphyletic group of toothed whales (Odontoceti) that represent independent secondary invasions of freshwater habitats. Different "river dolphin" lineages display suites of convergent morphological specializations that commonly reflect adaptations to riverine and freshwater environments, such as longirostry, reduced orbits, and wide, paddle-like flippers. One lineage, the Iniidae, is presently endemic to South America, and includes several extinct Neogene taxa along with their sole extant genus, Inia (the Amazon River dolphin). We report here a humerus recovered from the late Miocene deposits of the Ituzaingo Formation in the Parana Basin of Argentina. The specimen exhibits diagnostic features of the family Iniidae, including a scapular-sternal joint of the humerus, which is a unique anatomical connection among mammals. This joint permits enhanced parasagittal adduction of the flipper as a control surface, relative to other odontocetes, providing Inia with a high degree of maneuverability in its structurally complex and heterogenous riverine habitat. This unique anatomical connection, here documented from the late Miocene ( 9 million years-6.5 million years old), not only provides the oldest diagnostic record for Iniidae, but it also indicates a similar habitat use for this lineage, a finding coincident with the current paleoenvironmental interpretation for the Ituzaingo Formation.

show abstract

A new pliocene dolphin (Cetacea: Pontoporiidae), from the Lee Creek Mine, North Carolina

Cited by 18 publications

References 12 publications

Isthminia panamensis, a new fossil inioid (Mammalia, Cetacea) from the Chagres Formation of Panama and the evolution of ‘river dolphins’ in the Americas

Isthminia panamensis, a new fossil inioid (Mammalia, Cetacea) from the Chagres Formation of Panama and the evolution of ‘river dolphins’ in the Americas

Scaldiporia vandokkumi, a new pontoporiid (Mammalia, Cetacea, Odontoceti) from the Late Miocene to earliest Pliocene of the Westerschelde estuary (The Netherlands)

The Antiquity of Riverine Adaptations in Iniidae (Cetacea, Odontoceti) Documented by a Humerus from the Late Miocene of the Ituzaingó Formation, Argentina

Contact Info

Product

Resources

About