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Extinct Animals News
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First nimravid skull from Asia
Maofelis cantonensis Averianov, Obraztsova, Danilov, Skutschas & Jin, 2016  *This image is copyright of its original author Abstract: "Maofelis cantonensis gen. and sp. nov. is described based on a complete cranium from the middle-upper Eocene Youganwo Formation of Maoming Basin, Guangdong Province, China. The new taxon has characters diagnostic for Nimravidae such as a short cat-like skull, short palate, ventral surface of petrosal dorsal to that of basioccipital, serrations on the distal carina of canine, reduced anterior premolars, and absence of posterior molars (M2-3). It is plesiomorphic nimravid taxon similar to Nimravidae indet. from Quercy (France) in having the glenoid pedicle and mastoid process without ventral projections, a planar basicranium in which the lateral rim is not ventrally buttressed, and P1 present. The upper canine is less flattened than in other Nimravidae. Maofelis cantonensis gen. and sp. nov. exemplifies the earliest stage of development of sabertooth specialization characteristic of Nimravidae. This taxon, together with other middle-late Eocene nimravid records in South Asia, suggests origin and initial diversification of Nimravidae in Asia. We propose that this group dispersed to North America in the late Eocene and to Europe in the early Oligocene. The subsequent Oligocene diversification of Nimravidae took place in North America and Europe, while in Asia this group declined in the Oligocene, likely because of the earlier development of open habitats on that continent."
Out of Tibet: an early sheep from the Pliocene of Tibet, Protovis himalayensis, genus and species nov. (Bovidae, Caprini), and origin of Ice Age mountain sheep
Protovis himalayensis Wang, Li & Takeuchi, 2016  *This image is copyright of its original author Fig.2: Map of extinct and extant species of Ovis in Eurasia and their evolutionary relationships. (Image by WANG Xiaoming) Abstract: "Modern wild sheep, Ovis, is widespread in the mountain ranges of the Caucasus through Himalaya, Tibetan Plateau, Tianshan-Altai, eastern Siberia, and the Rocky Mountains in North America. In Eurasia, fossil sheep are known at a few Pleistocene sites in North China, eastern Siberia, and western Europe, but are so far absent from the Tibetan Plateau. We describe an extinct sheep, Protovis himalayensis, gen. et sp. nov., from the Pliocene of the Zanda Basin in western Himalaya. Smaller than the living argali, this new form shares with Ovis posterolaterally arched horncores and partially developed sinuses and possesses several transitional characters leading to Ovis. Protovis likely subsisted on C3 plants, which are the dominant vegetation in the Zanda area during the Pliocene. With the discovery of this new genus and species, we extend the fossil record for the sheep clade into the Pliocene of the Tibetan Plateau, consistent with our previous out-of-Tibet hypothesis. Ancestral sheep in the Pliocene were presumed adapted to high altitude and cold environments, and during the Ice Age, sheep became anatomically modern and dispersed outside of the Tibetan Plateau. Both this new fossil datum and the existing molecular phylogeny suggest that the Tibetan Plateau, possibly including Tianshan-Altai, represents the ancestral home range(s) of mountain sheep and that these basal stocks were the ultimate source of all extant species. Most sheep species survived along their Pleistocene route of dispersal, offering a highly consistent pattern of zoogeography." Other articles related: New Species from the Pliocene of Tibet Reveals Origin of Ice Age Mountain Sheep New species from the Pliocene of Tibet reveals origin of Ice Age mountain sheep
Watch Divers Find Sloth Fossils in Underwater Cave
"Rare Find: Extinct Sloth Fossils Discovered In Underwater Cave. Divers made a rare discovery of extinct giant sloths in a Cuban cave. Geographer and National Geographic grantee Matthew Peros and his team found fossils of three extinct sloth species in an underwater cave near Varadero. Underwater caves with extinct animal remains are extremely rare. Peros hopes to learn more about ancient climate and environment from studying the remains." Amazing video 
http://www.telegraph.co.uk/news/2016/05/...r-recorde/
19 MAY 2016 • 9:12AM Scientists on Wednesday said they have found the remains of a giant prehistoric bird that lived 50 million years ago in Antarctica and had the largest wingspan ever recorded. Paleontologists at a natural history museum in Argentina said they had identified the pelagornithid, or bony-toothed bird, nearly three years after its fossilised bones were first found at an Argentine research base on the Antarctic island of Marambio. "Almost three years ago, remains began to appear of what we believed could be this bird. Then we found a bone that confirmed that it was a pelagornithid," an extinct family of enormous seabirds, said Carolina Acosta Hospitaleche, a researcher on the project. The bird's wings, fully extended, spanned more than 6.4 metres (21 feet), she said.
A new family of bizarre durophagous carnivorous marsupials from Miocene deposits in the Riversleigh World Heritage Area, northwestern Queensland
Malleodectes mirabilis Archer et al., 2016  *This image is copyright of its original author Fig.6: Malleodectes mirabilis using its massive, ball-peen-like P3 to break into what were perhaps one of this unique Miocene marsupial’s favourite meals — Riversleigh escargots. Reconstruction credits: Peter Schouten Abstract: "A new specimen of the bizarrely specialised Malleodectes mirabilis from middle Miocene deposits in the Riversleigh World Heritage Area provides the first and only information about the molar dentition of this strange group of extinct marsupials. Apart from striking autapomorphies such as the enormous P3, other dental features such as stylar cusp D being larger than B suggest it belongs in the Order Dasyuromorphia. Phylogenetic analysis of 62 craniodental characters places Malleodectes within Dasyuromorphia albeit with weak support and without indication of specific relationships to any of the three established families (Dasyuridae, Myrmecobiidae and Thylacinidae). Accordingly we have allocated Malleodectes to the new family, Malleodectidae. Some features suggest potential links to previously named dasyuromorphians from Riversleigh (e.g., Ganbulanyi) but these are too poorly known to test this possibility. Although the original interpretation of a steeply declining molar row in Malleodectes can be rejected, it continues to seem likely that malleodectids specialised on snails but probably also consumed a wider range of prey items including small vertebrates. Whatever their actual diet, malleodectids appear to have filled a niche in Australia’s rainforests that has not been occupied by any other mammal group anywhere in the world from the Miocene onwards." Other articles related: Remains of bizarre group of extinct snail-eating Australian marsupials discovered Hammer-toothed ‘marsupial skinks' from the Australian Cenozoic Hammer-toothed skink SMASH!
A second endemic land mammal for the Hawaiian Islands: a new genus and species of fossil bat (Chiroptera: Vespertilionidae)
Synemporion keana Ziegler, Howarth & Simmons, 2016  *This image is copyright of its original author FIGURE 10. Skeleton of Synemporion keana in situ on the floor near the lower end of Māhiehie Cave. Credits: Ziegler et al.  *This image is copyright of its original author FIGURE 2. Lateral views of the skull and left dentary of A, the holotype of Synemporion keana (BPBM 159269) compared with B, Lasiurus cinereus semotus (BPBM 184506). Note the difference in the rostral profile between the two species, including the more robust lower jaw dentition in Lasiurus compared with Synemporion. Credits: Ziegler et al. Abstract: "Located over 3800 km from the nearest continent, the Hawaiian Islands have previously been thought to support only one endemic land mammal, the extant Hawaiian hoary bat (Lasiurus cinereus semotus), a taxon that apparently initially dispersed from mainland North America between 10,000 and 7000 years ago. Some uncertainty exists regarding the status of this taxon (i.e., whether or not populations representing more recent invasions of L. cinereus from North America are exchanging genes with the older lineage, and whether or not semotus represents a distinct species), but all researchers agree that hoary bats are the only endemic land mammals extant in the islands today. However, fossil evidence indicates that the Hawaiian Islands once supported another quite different endemic bat species that is now extinct. Skeletal remains of a new genus and species of vespertilionid bat are herein described from various Late Pleistocene and Holocene/Recent deposits on the five largest Hawaiian Islands. The new taxon is diagnosed by a mosaic of features including dental formula, molar morphology, skull shape, and metacarpal formula. This new taxon, which is smaller than Hawaiian hoary bat, was apparently present in the Hawaiian Islands by 320,000 years b.p. and survived until at least 1100 years ago and possibly much later. Accordingly, two species of bats coexisted on the Hawaiian Islands for several thousand years. As with numerous extinct endemic bird species, the extinction of the new bat taxon described here may have resulted either directly or indirectly from human colonization of the islands and the invasive nonnative species that came with human explorers and settlers." Full article Other articles related: Discovery of extinct bat doubles diversity of native Hawaiian land mammals Discovery of extinct bat doubles diversity of native Hawaiian land mammals
A new nothrotheriid xenarthran from the early Pliocene of Pomata-Ayte (Bolivia): new insights into the caniniform–molariform transition in sloths
Aymaratherium jeani Pujos et al., 2016  *This image is copyright of its original author Abstract: "Tardigrade xenarthrans are today represented only by the two tree sloth genera Bradypus and Choloepus, which inhabit the Neotropical rainforests and are characterized by their slowness and suspensory locomotion. Sloths havebeen recognized in South America since the early Oligocene. This monophyletic group is represented by five clades traditionally recognized as families: Bradypodidae, Megalonychidae, Mylodontidae (†), Megatheriidae (†) and Nothrotheriidae (†). A new nothrotheriid ground sloth represented by a dentary and several postcranial elements, Aymaratherium jeani gen. nov., sp. nov., from the early Pliocene locality of Pomata-Ayte (Bolivia) is reported. This small- to medium-sized species is characterized especially by its dentition and several postcranial features. It exhibits several convergences with the ‘aquatic’ nothrotheriid sloth Thalassocnus and the giant megatheriid ground sloth Megatherium (M.) americanum, and is interpreted as a selective feeder, with good pronation and supination movements. The tricuspid caniniform teeth of Aymaratherium may represent a transitional stage between the caniniform anterior teeth of basal megatherioids and basal nothrotheriids (1/1C-4/3M as in Hapalops or Mionothropus) and the molariform anterior teeth of megatheriids (5/4M, e.g. Megatherium). To highlight the phylogenetic position of this new taxon among nothrotheriid sloths, we performed a cladistic assessment of the available dental and postcranial evidence. Our results, derived from a TNT treatment of a data matrix largely based on a published phylogenetic data set, indicate that Aymaratherium is either sister taxon to Mionothropus or sister to the clade Nothrotheriini within Nothrotheriinae. They further support the monophyly of both the Nothrotheriinae and the Nothrotheriini, as suggested previously by several authors."
The anatomy and taxonomy of the exquisitely preserved Green River Formation (early Eocene) lithornithids (Aves) and the relationships of Lithornithidae
Calciavis grandei Nesbitt & Clarke, 2016  *This image is copyright of its original author A Green River Formation lithornithid Calciavis grandei standing by the shores of the Eocene Fossil Lake (~ 50 Ma) with a small rallid in the background. Reconstruction credits: Velizar Simeonovski  *This image is copyright of its original author A nearly complete skeleton of Calciavis grandei, a close relative of ostriches, kiwis, and emus. Photo credits: Rick Edwards  *This image is copyright of its original author A Lithornithid skull from the Green River Formation of Wyoming. Photo credits: Sterling Nesbitt Abstract: "Fossil remains of Paleogene Palaeognathae are poorly documented and are exceedingly rare. One group of palaeognaths, the lithornithids, is well represented in the Paleogene of North America. Nevertheless, few specimens of the same species are known from each of those Paleogene geologic units. Here, we report five new partial skeletons of lithornithids from the Fossil Butte Member of the Green River Formation (early Eocene) of Wyoming. One spectacularly preserved specimen is identified as the holotype of a new species, Calciavis grandei, gen. et sp. nov., and fully described. Preserved soft tissues (e.g., feathers, pes scales) surround the nearly articulated and complete skeleton. A second well-preserved but disarticulated skeleton is referred to this new taxon. We conclude that there are only two lithornithid taxa in the Green River Formation after careful comparisons with the other known taxon from the same geological unit, Pseudocrypturus cercanaxius. Morphological data generated from the new taxon and other Green River Formation lithornithid specimens were integrated into a osteology-only phylogenetic data set containing stem avians as outgroups and extinct and extant members of Palaeognathae (Tinamidae, ratites) and Neognathaes (Anseriformes, Galliformes, Neoaves), unnamed lithornithid specimens, and the following named lithornithid taxa: Lithornis plebius, Lithornis promiscuus, Lithornis celetius, Paracathartes howardae. We find a monophyletic Lithornithidae (containing Calciavis grandei, Pseudocrypturus cercanaxius, Lithornis plebius, Lithornis promiscuus, Lithornis celetius, Paracathartes howardae) as the sister taxon of Tinamidae at the base of Palaeognathae and also recover a monophyletic Ratitae in the morphology-only analysis. A Lithornithidae-Tinamidae relationship, which could imply a broad Northern Hemisphere distribution in the Paleogene for this total group retracted to the present day Neotropical distribution after the Eocene, is weakly supported in our analysis and is also supported by other lines of evidence such as eggshell morphology. Relationships among flightless palaeognaths and assessment of character homology in this group remain problematic. Indeed, when the morphological analyses were constrained to enforce topologies recovered from all recent analyses of molecular sequence data and retroelement insertions, Lithornithidae is no longer recovered with Tinamidae, which is nested within the now paraphyletic ratites, but remains at the base of Palaeognathae. Thus, regardless of the position of Tinamidae, Lithornithidae is recovered at the base of the clade. However, evidence that many, if not all, of these "ratite" lineages independently evolved similar morphologies related to large size and flight loss suggests that the proposed position of the Lithornithidae remains tentative. Significant morphological variation within Lithornithidae should be captured in inclusive future analyses through use of species terminals." Images HD Other articles related: Well-preserved fossils show ostrich relatives lived in North America 50 million years ago Ostrich relative lived in North America about 50 million years ago Calciavis grandei: Kiwi Relatives Lived in North America 50M Years Ago
Fossorial Origin of the Turtle Shell Lyson et al. 2016
 *This image is copyright of its original author An ancient reptile (Eunotosaurus africanus), a precursor to today’s turtles, had a body well-suited to burrowing, as illustrated here. (Another extinct reptile, Bradysaurus, is shown in the background.) Reconstruction credits: Andrey Atuchin Highlights • Recently discovered stem turtles indicate the shell did not evolve for protection • Adaptation related to digging was the initial impetus in the origin of the shell • Digging adaptations facilitated the movement of turtles into aquatic environments • Fossoriality likely helped stem turtles survive the Permian/Triassic extinction Summary "The turtle shell is a complex structure that currently serves a largely protective function in this iconically slow-moving group [ 1 ]. Developmental [ 2, 3 ] and fossil [ 4–7 ] data indicate that one of the first steps toward the shelled body plan was broadening of the ribs (approximately 50 my before the completed shell [ 5 ]). Broadened ribs alone provide little protection [ 8 ] and confer significant locomotory [ 9, 10 ] and respiratory [ 9, 11 ] costs. They increase thoracic rigidity [ 8 ], which decreases speed of locomotion due to shortened stride length [ 10 ], and they inhibit effective costal ventilation [ 9, 11 ]. New fossil material of the oldest hypothesized stem turtle, Eunotosaurus africanus [ 12 ] (260 mya) [ 13, 14 ] from the Karoo Basin of South Africa, indicates the initiation of rib broadening was an adaptive response to fossoriality. Similar to extant fossorial taxa [ 8 ], the broad ribs of Eunotosaurus provide an intrinsically stable base on which to operate a powerful forelimb digging mechanism. Numerous fossorial correlates [ 15–17 ] are expressed throughout Eunotosaurus’ skeleton. Most of these features are widely distributed along the turtle stem and into the crown clade, indicating the common ancestor of Eunotosaurus and modern turtles possessed a body plan significantly influenced by digging. The adaptations related to fossoriality likely facilitated movement of stem turtles into aquatic environments early in the groups’ evolutionary history, and this ecology may have played an important role in stem turtles surviving the Permian/Triassic extinction event." Other articles related: Why the turtle got its shell Why Turtles Evolved Shells: It Wasn't for Protection
Neotropics provide insights into the emergence of New World monkeys: New dental evidence from the late Oligocene of Peruvian Amazonia
Canaanimico amazonensis Marivaux et al., 2016  *This image is copyright of its original author Abstract: "Recent field efforts in Peruvian Amazonia (Contamana area, Loreto Department) have resulted in the discovery of a late Oligocene (ca. 26.5 Ma; Chambira Formation) fossil primate-bearing locality (CTA-61). In this paper, we analyze the primate material consisting of two isolated upper molars, the peculiar morphology of which allows us to describe a new medium-sized platyrrhine monkey: Canaanimico amazonensis gen. et sp. nov. In addition to the recent discovery of Perupithecus ucayaliensis, a primitive anthropoid taxon of African affinities from the alleged latest Eocene Santa Rosa locality (Peruvian Amazonia), the discovery of Canaanimico adds to the evidence that primates were well-established in the Amazonian Basin during the Paleogene. Our phylogenetic results based on dental evidence show that none of the early Miocene Patagonian taxa (Homunculus, Carlocebus, Soriacebus, Mazzonicebus, Dolichocebus, Tremacebus, and Chilecebus), the late Oligocene Bolivian Branisella, or the Peruvian Canaanimico, is nested within a crown platyrrhine clade. All these early taxa are closely related and considered here as stem Platyrrhini. Canaanimico is nested within the Patagonian Soriacebinae, and closely related to Soriacebus, thereby extending back the soriacebine lineage to 26.5 Ma. Given the limited dental evidence, it is difficult to assess if Canaanimico was engaged in a form of pitheciine-like seed predation as is observed in Soriacebus and Mazzonicebus, but dental microwear patterns recorded on one upper molar indicate that Canaanimico was possibly a fruit and hard-object eater. If Panamacebus, a recently discovered stem cebine from the early Miocene of Panama, indicates that the crown platyrrhine radiation was already well underway by the earliest Miocene, Canaanimico indicates in turn that the “homunculid” radiation (as a part of the stem radiation) was well underway by the late Oligocene. These new data suggest that the stem radiation likely occurred in the Neotropics during the Oligocene, and that several stem lineages independently reached Patagonia during the early Miocene. Finally, we are still faced with a “layered” pattern of platyrrhine evolution, but modified in terms of timing of cladogeneses. If the crown platyrrhine radiation occurred in the Neotropics around the Oligocene–Miocene transition (or at least during the earliest Miocene), it was apparently concomitant with the diversification of the latest stem forms in Patagonia." Full article
A new Old World vulture from the late Miocene of China sheds light on Neogene shifts in the past diversity and distribution of the Gypaetinae
Mioneophron longirostris Li, Clarke, Zhou & Deng, 2016  *This image is copyright of its original author Abstract: "Neogene fossils of Old World vultures (Aegypiinae and Gypaetinae) are known from both Old World and New World records. There are no extant Old World vultures in the Americas today, although a large diversity of Gypaetinae is known from Miocene to late Pleistocene records. Despite a comparatively large number of North American gypaetine fossils, complete specimens have rarely been reported from Eurasia and Africa. We describe the exceptional skeleton of a new gypaetine vulture from the late Miocene deposits of the Linxia Basin in northwestern China. The specimen is the oldest record of Gypaetinae from Eurasia or Africa. A reexamination of the geographic and temporal distribution of most Old World vultures from Neogene deposits indicates a diverse radiation, coincident with early- to mid-Miocene grassland expansion for Gypaetinae. Although the diversification of Aegypiinae has been linked to the transition from C3 to C4 grassland, Gypaetinae diversification predates that transition in both North America and Asia. A shift in the known latitudinal distribution is also noted. Neogene records of Old World vultures are found primarily in mid- and high-latitude regions of North America and Eurasia as well as in the middle and low latitudes of Eurasia and Africa. With very few records in the middle to late Miocene, a latitudinal distribution similar to that of extant species is first seen in the early Pliocene. The new fossil provides further temporal constraints on avian subclade diversification. It is also consistent with an emerging pattern of profound recent shifts in avian diversity and distribution more generally." Full article
Synchrotron analysis of a ‘mummified’ salamander (Vertebrata: Caudata) from the Eocene of Quercy, France
Phosphotriton sigei Tissier et al. 2016  *This image is copyright of its original author Figure 4. Three-dimensional reconstruction of the skeleton of Phosphotriton sigei gen. et sp. nov. (B), scaled to the same length as other Eurasian urodeles: a European plethodontid, Hydromantes italicus Dunn, 1923 (A), and two salamandrids, Hypselotriton orientalis (David, 1873) © and Salamandra salamandra (Linnaeus, 1758) (D). Abstract: "An incomplete ‘mummy’ from the Phosphorites du Quercy (presumed Eocene) was identified as a salamander during the 19th century. The specimen has now been computed tomography (CT) scanned, and this revealed the incomplete skeleton (with perfectly preserved bones) and soft tissues (lung). The fossil represents a new, well-characterized taxon. Despite the absence of the skull, several features allow a phylogenetic analysis. The fossil belongs to pseudosaurian caudates; it is tentatively assigned to the Salamandridae, although affinities with Plethodontidae cannot be definitely ruled out." Full article
A new side-neck turtle (Pelomedusoides: Bothremydidae) from the Early Paleocene (Danian) Maria Farinha Formation, Paraíba Basin, Brazil
Inaechelys pernambucensis Carvalho, Ghilardi & Barreto 2016  *This image is copyright of its original author Reconstruction credits: Julio Lacerda Abstract: "Limestone and marl from Maria Farinha Formation (Paraíba Basin, NE Brazil) accumulated in a shallow continental shelf environment during the expansion of the Atlantic Ocean in early Paleocene (Danian). It contains a rich paleontological record, which comprises many marine invertebrates, several species of bony and cartilaginous fishes, a crocodyliform and turtle remains. Here, we describe a new genus and species of pleurodire turtle from Maria Farinha Formation, based on a nearly complete plastron, an incomplete left pelvic girdle, and four dermal plates of the carapace. We tested the phylogenetic position of Inaechelys pernambucensis gen. et sp. nov. by including it in a comprehensive cladistic analysis of pleurodires. The new species is included within Botrhemydidae, with affinities to Bothremydini, positioned as sister group of Rosasia soutoi. Inaechelys pernambucensis gen. et sp. nov. differs from R. soutoi for the almost straight anterior lobe cranial edge of its plastron, as well as for its pentagonal shaped entoplastron and its abdominal shield midline, which is considerably smaller than the respective femoral shield midline. Inaechelys pernambucensis is the first turtle species formally described from Brazilian Paleocene strata. Within Bothremydidae, it is also the first conclusively fully marine species described for this country. This new record contributes to the understanding of the ecology and paleobiogeographical distribution of Bothremydidae family." Full Article Other articles related: Brazilian side-necked turtle thrived after dinosaur extinction
Three terrestrial Pleistocene coucals (Centropus: Cuculidae) from southern Australia: biogeographical and ecological significance Shude, Prideaux & Worthy, 2016
 *This image is copyright of its original author Thunder thighs: The femur of a modern Pheasant Coucal Centropus phasianinus (left) looks puny next to the bones of the extinct Nullarbor species Centropus bairdi (middle) and Centropus maximus (right). Photo credits: Elen Shute Abstract: "Coucals are large, predatory, primarily ground-dwelling cuckoos of the genus Centropus, with 26 extant species ranging from Africa to Australia. Their evolutionary and biogeographical history are poorly understood and their fossil record almost non-existent. Only one species (Centropus phasianinus) currently inhabits Australia, but there is now fossil evidence for at least three Pleistocene species. One of these (Centropus colossus) was described from south-eastern Australia in 1985. Here we describe additional elements of this species from the same site, and remains of two further extinct species from the Thylacoleo Caves of the Nullarbor Plain, south-central Australia. The skeletal morphology and large size of the three extinct species indicates that they had reduced capacity for flight and were probably primarily ground-dwelling. The extinct species include the two largest-known cuckoos, weighing upwards of 1 kg each. They demonstrate that gigantism in this lineage has been more marked in a continental context than on islands, contrary to the impression gained from extant species. The evolutionary relationships of the Australian fossil coucals are uncertain, but our phylogenetic analysis indicates a possible close relationship between one of the Nullarbor species and extant Centropus violaceus from the Bismarck Archipelago. The presence of three coucals in southern Australia markedly extends the geographical range of the genus from tropical Australia into southern temperate regions. This demonstrates the remarkable and consistent ability of coucals to colonize continents despite their very limited flying ability." Full article Other articles related: The world’s biggest cuckoos once roamed the Nullarbor Plain
The Origin of High-Frequency Hearing in Whales
Echovenator sandersi Churchill, Martinez-Caceres, de Muizon, Mnieckowski & Geisler, 2016  *This image is copyright of its original author Reconstruction credits: A. Gennari 2016  *This image is copyright of its original author Skull. Highlights •An ancient toothed whale is described, which possesses a well-preserved inner ear •Features associated with ultrasonic hearing are preserved in the ear of this whale •Ultrasonic hearing evolved with echolocation in the first toothed whales •Hearing at higher frequencies began in the ancestors of toothed whales Summary "Odontocetes (toothed whales) rely upon echoes of their own vocalizations to navigate and find prey underwater [ 1 ]. This sensory adaptation, known as echolocation, operates most effectively when using high frequencies, and odontocetes are rivaled only by bats in their ability to perceive ultrasonic sound greater than 100 kHz [ 2 ]. Although features indicative of ultrasonic hearing are present in the oldest known odontocetes [ 3 ], the significance of this finding is limited by the methods employed and taxa sampled. In this report, we describe a new xenorophid whale (Echovenator sandersi, gen. et sp. nov.) from the Oligocene of South Carolina that, as a member of the most basal clade of odontocetes, sheds considerable light on the evolution of ultrasonic hearing. By placing high-resolution CT data from Echovenator sandersi, 2 hippos, and 23 fossil and extant whales in a phylogenetic context, we conclude that ultrasonic hearing, albeit in a less specialized form, evolved at the base of the odontocete radiation. Contrary to the hypothesis that odontocetes evolved from low-frequency specialists [ 4 ], we find evidence that stem cetaceans, the archaeocetes, were more sensitive to high-frequency sound than their terrestrial ancestors. This indicates that selection for high-frequency hearing predates the emergence of Odontoceti and the evolution of echolocation." Other articles related: Echo hunter: Researchers name new fossil whale with high frequency hearing |
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