The modern giant sperm whale Physeter macrocephalus, one of the largest known predators, preys up... more The modern giant sperm whale Physeter macrocephalus, one of the largest known predators, preys upon cephalopods at great depths. Lacking a functional upper dentition, it relies on suction for catching its prey; in contrast, several smaller Miocene sperm whales (Physeteroidea) have been interpreted as raptorial (versus suction) feeders, analogous to the modern killer whale Orcinus orca. Whereas very large physeteroid teeth have been discovered in various Miocene localities, associated diagnostic cranial remains have not been found so far. Here we report the discovery of a new giant sperm whale from the Middle Miocene of Peru (approximately 12–13 million years ago), Leviathan melvillei, described on the basis of a skull with teeth and mandible. With a 3-m-long head, very large upper and lower teeth (maximum diameter and length of 12 cm and greater than 36 cm, respectively), robust jaws and a temporal fossa considerably larger than in Physeter, this stem physeteroid represents one of t...
Apart from a few exceptions, extant odontocetes (toothed cetaceans) exhibit a roughly homodont de... more Apart from a few exceptions, extant odontocetes (toothed cetaceans) exhibit a roughly homodont dentition. The transition from basilosaurid-like double-rooted cheek teeth with accessory denticles to single-rooted conical teeth occurred during the late Oligocene-early Miocene. At that time, several clades of now extinct, homodont and predominantly long-snouted odontocetes appeared in the fossil record. Among them, members of the genera Argyrocetus Lydekker, 1893 and Macrodelphinus Wilson, 1935, from the early Miocene of the Northeast Pacific and Argentina, were tentatively attributed to the family Eurhinodelphinidae. However, due to the fragmentary state of the specimens, unambiguous apomorphies of the family could not be detected. Based on two well-preserved skulls with associated mandibular elements, discovered in early Miocene layers of the Chilcatay Formation (Pisco Basin, Peru), we report on a new genus and species of long-snouted homodont odontocete, Chilcacetus cavirhinus n. ge...
The taphonomy and palaeoecology of the early Miocene (Burdigalian) vertebrate assemblage of Ulluj... more The taphonomy and palaeoecology of the early Miocene (Burdigalian) vertebrate assemblage of Ullujaya (East Pisco Basin, Peru) is here described. Vertebrate remains are concentrated in marine facies (Ct1a association) of the exposed Chilcatay Formation (dated 19–18 Ma) deposited within a 30–40 m deep, semi-enclosed, offshore environment. Coupled with ichnological observations, the size distribution of pyrite framboid relics reveals fluctuation of euxinic and oxic-dysoxic conditions at the seafloor. The assemblage is dominated by toothed cetaceans (kentriodontids, squalodelphinids, physeteroids, and the eurhinodelphinid-like Chilcacetus), together with a large dermochelyid turtle, some bony fish, and diverse elasmobranchs, mostly juveniles of Carcharhinus brachyurus and Cosmopolitodus hastalis. The vertebrate assemblage comprises a coastal community, dominated by mesopredators, representative of a warm-temperate, sheltered embayment connected with riverine and open-ocean environments....
The northward-flowing Humboldt Current hosts perpetually high levels of productivity along the we... more The northward-flowing Humboldt Current hosts perpetually high levels of productivity along the western coast of South America. Here, we aim to elucidate the deep-time history of this globally important ecosystem based on a detailed palaeoecological analysis of the exceptionally preserved middle–upper Miocene vertebrate assemblages of the Pisco Formation of the East Pisco Basin, southern Peru. We summarise observations on hundreds of fossil whales, dolphins, seals, seabirds, turtles, crocodiles, sharks, rays, and bony fishes to reconstruct ecological relationships in the wake of the Middle Miocene Climatic Optimum, and the marked cooling that followed it. The lowermost, middle Miocene Pisco sequence (P0) and its vertebrate assemblage testify to a warm, semi-enclosed, near-shore palaeoenvironment. During the first part of the Tortonian (P1), high productivity within a prominent upwelling system supported a diverse assemblage of mesopredators, at least some of which permanently resided...
Invertebrate taphonomy can provide significant information about the post-mortem processes that a... more Invertebrate taphonomy can provide significant information about the post-mortem processes that affected the fossil record. In the East Pisco Basin of southern Peru, a Panopea Ménard de la Groye, 1807 shell bed was found in the upper Miocene strata of the Pisco Formation, hinting at a peculiar biostratinomic and diagenetic history. This bed contains abundant invertebrate fossil molds cemented by dolomite. The specimens of the deep infaunal bivalve, Panopea sp., occur together with bivalves representative of shallow infaunal species (Trachycardium sp. and Dosinia ponderosa [Gray, 1838]) and balanid barnacles, which are sessile encrusters. The Panopea specimens host compound molds evidencing an abundant encrusting fauna, including serpulids, ?foraminifera, bryozoans, and barnacles that colonized the inner surfaces of the valves before their final burial. We hypothesize that short-term, storm-related processes exhumed the living bivalves, resulting in a sedimentological concentration o...
Several aspects of the fascinating evolutionary history of toothed and baleen whales (Cetacea) ar... more Several aspects of the fascinating evolutionary history of toothed and baleen whales (Cetacea) are still to be clarified due to the fragmentation and discontinuity (in space and time) of the fossil record. Here we open a window on the past, describing a part of the extraordinary cetacean fossil assemblage deposited in a restricted interval of time (19–18 Ma) in the Chilcatay Formation (Peru). All the fossils here examined belong to the Platanistoidea clade as here redefined, a toothed whale group nowadays represented only by the Asian river dolphin Platanista gangetica. Two new genera and species, the hyper-longirostrine Ensidelphis riveroi and the squalodelphinid Furcacetus flexirostrum, are described together with new material referred to the squalodelphinid Notocetus vanbenedeni and fragmentary remains showing affinities with the platanistid Araeodelphis. Our cladistic analysis defines the new clade Platanidelphidi, sister-group to Allodelphinidae and including E. riveroi and the...
ABSTRACT In contrast to the suction-feeding, predominantly teuthophagous extant sperm whale, seve... more ABSTRACT In contrast to the suction-feeding, predominantly teuthophagous extant sperm whale, several Miocene physeteroids display proportionally larger teeth, deeply embedded in both upper and lower jaws. Together with other osteological features, these differences lead to the functional interpretation of these taxa as macroraptorial predators, using their teeth to capture and process large marine vertebrates. However, the assumption that strong forces applied to macroraptorial physeteroid teeth during powerful bites and contacts with bone material should result in major dental damage has not yet been tested. In the present work, we analyzed a large collection of physeteroid teeth with an enameled crown from the Miocene of the North Sea Basin. We especially focused on a set of 45 teeth of Scaldicetus caretti discovered in Antwerp (Belgium, southern North Sea Basin) and tentatively dated to the Tortonian (early late Miocene). Visual inspection and computed tomography (CT) scans revealed dental damage, including wear and breaks. The latter could be interpreted as chipping fractures, occurring along the crown, and vertical root fractures, observed along the apical part of the massive root. Chipping fractures are most likely due to contacts with hard material, whereas vertical root fractures may result from the application of strong and repetitive bite forces and/or contacts with hard material. Such results further support the interpretation of a series of Miocene physeteroids with proportionally large teeth as macroraptorial (rather than suction-feeding) top predators. Considering the size of the teeth of S. caretti, its most likely prey items were other large marine vertebrates.
Baleen whales (Mysticeti) are major ecosystem engineers, thanks to their enormous size and bulk f... more Baleen whales (Mysticeti) are major ecosystem engineers, thanks to their enormous size and bulk filter feeding strategy. Their signature gigantism is thought to be a relatively recent phenomenon, resulting from a Plio-Pleistocene mode shift in their body size evolution. Here, we report the largest whale fossil ever described: an Early Pleistocene (1.5–1.25 Ma) blue whale from Italy with an estimated body length of up to 26 m. Macroevolutionary modelling taking into account this specimen, as well as additional material from the Miocene of Peru, reveals that the proposed mode shift occurred either somewhat earlier, or perhaps not at all. Large-sized mysticetes comparable to most extant species have existed since at least the Late Miocene, suggesting a long-term impact on global marine ecosystems.
Coronuloid barnacles are epibionts of several marine vertebrates (including cetaceans and sea tur... more Coronuloid barnacles are epibionts of several marine vertebrates (including cetaceans and sea turtles) as well as invertebrates, and are assigned to two families of turtle barnacles (Chelonibiidae Pilsbry, 1916 and Platylepadidae Newman & Ross, 1976) and one family of whale barnacles (Coronulidae Leach, 1817). Chelonibiids and coronulids have a scanty, albeit significant fossil record extending back to the Eocene and Pliocene, respectively; in turn, the fossil record of platylepadids is limited to a single record from the Upper Pleistocene. Here we report on an isolated carinolateral compartment of Platylepas Gray, 1825, the type genus of the family, from Lower Pleistocene (Gelasian) epibathyal deposits exposed at Milazzo (Sicily, Italy). This specimen is here designated holotype of a new species, †Platylepas mediterranea sp. nov. We argue that, like most extant members of Platylepas, †P. mediterranea sp. nov. lived partially embedded in the skin of a sea turtle. This record of an e...
The upper Neogene Pisco Formation of Peru is known worldwide as one of the most significant Cenoz... more The upper Neogene Pisco Formation of Peru is known worldwide as one of the most significant Cenozoic marine vertebrate Konservatt-Lagerstätten, even featuring cetacean specimens that retain remains of soft tissues or stomach contents. Previous works showed that biomediated precipitation of dolomite concretions around large-sized decaying carcasses was one of the most relevant processes responsible for exceptional fossil preservation. In turn, little is known about the modes of fossilization of well-preserved small-sized vertebrates, which are rather common in the Pisco Formation, but mostly do not exhibit dolomite concretions. We report on a cetacean specimen, identified as belonging to the extinct short-snouted, small dolphin species Brachydelphis mazeasi (Pontoporiidae), preserved within a late Miocene sandy deposit at the site of Pampa Corre Viento. This specimen consists of a moderately disarticulated partial skeleton exhibiting well-mineralized bones; it is not enclosed within ...
The modern giant sperm whale Physeter macrocephalus, one of the largest known predators, preys up... more The modern giant sperm whale Physeter macrocephalus, one of the largest known predators, preys upon cephalopods at great depths. Lacking a functional upper dentition, it relies on suction for catching its prey; in contrast, several smaller Miocene sperm whales (Physeteroidea) have been interpreted as raptorial (versus suction) feeders, analogous to the modern killer whale Orcinus orca. Whereas very large physeteroid teeth have been discovered in various Miocene localities, associated diagnostic cranial remains have not been found so far. Here we report the discovery of a new giant sperm whale from the Middle Miocene of Peru (approximately 12–13 million years ago), Leviathan melvillei, described on the basis of a skull with teeth and mandible. With a 3-m-long head, very large upper and lower teeth (maximum diameter and length of 12 cm and greater than 36 cm, respectively), robust jaws and a temporal fossa considerably larger than in Physeter, this stem physeteroid represents one of t...
Apart from a few exceptions, extant odontocetes (toothed cetaceans) exhibit a roughly homodont de... more Apart from a few exceptions, extant odontocetes (toothed cetaceans) exhibit a roughly homodont dentition. The transition from basilosaurid-like double-rooted cheek teeth with accessory denticles to single-rooted conical teeth occurred during the late Oligocene-early Miocene. At that time, several clades of now extinct, homodont and predominantly long-snouted odontocetes appeared in the fossil record. Among them, members of the genera Argyrocetus Lydekker, 1893 and Macrodelphinus Wilson, 1935, from the early Miocene of the Northeast Pacific and Argentina, were tentatively attributed to the family Eurhinodelphinidae. However, due to the fragmentary state of the specimens, unambiguous apomorphies of the family could not be detected. Based on two well-preserved skulls with associated mandibular elements, discovered in early Miocene layers of the Chilcatay Formation (Pisco Basin, Peru), we report on a new genus and species of long-snouted homodont odontocete, Chilcacetus cavirhinus n. ge...
The taphonomy and palaeoecology of the early Miocene (Burdigalian) vertebrate assemblage of Ulluj... more The taphonomy and palaeoecology of the early Miocene (Burdigalian) vertebrate assemblage of Ullujaya (East Pisco Basin, Peru) is here described. Vertebrate remains are concentrated in marine facies (Ct1a association) of the exposed Chilcatay Formation (dated 19–18 Ma) deposited within a 30–40 m deep, semi-enclosed, offshore environment. Coupled with ichnological observations, the size distribution of pyrite framboid relics reveals fluctuation of euxinic and oxic-dysoxic conditions at the seafloor. The assemblage is dominated by toothed cetaceans (kentriodontids, squalodelphinids, physeteroids, and the eurhinodelphinid-like Chilcacetus), together with a large dermochelyid turtle, some bony fish, and diverse elasmobranchs, mostly juveniles of Carcharhinus brachyurus and Cosmopolitodus hastalis. The vertebrate assemblage comprises a coastal community, dominated by mesopredators, representative of a warm-temperate, sheltered embayment connected with riverine and open-ocean environments....
The northward-flowing Humboldt Current hosts perpetually high levels of productivity along the we... more The northward-flowing Humboldt Current hosts perpetually high levels of productivity along the western coast of South America. Here, we aim to elucidate the deep-time history of this globally important ecosystem based on a detailed palaeoecological analysis of the exceptionally preserved middle–upper Miocene vertebrate assemblages of the Pisco Formation of the East Pisco Basin, southern Peru. We summarise observations on hundreds of fossil whales, dolphins, seals, seabirds, turtles, crocodiles, sharks, rays, and bony fishes to reconstruct ecological relationships in the wake of the Middle Miocene Climatic Optimum, and the marked cooling that followed it. The lowermost, middle Miocene Pisco sequence (P0) and its vertebrate assemblage testify to a warm, semi-enclosed, near-shore palaeoenvironment. During the first part of the Tortonian (P1), high productivity within a prominent upwelling system supported a diverse assemblage of mesopredators, at least some of which permanently resided...
Invertebrate taphonomy can provide significant information about the post-mortem processes that a... more Invertebrate taphonomy can provide significant information about the post-mortem processes that affected the fossil record. In the East Pisco Basin of southern Peru, a Panopea Ménard de la Groye, 1807 shell bed was found in the upper Miocene strata of the Pisco Formation, hinting at a peculiar biostratinomic and diagenetic history. This bed contains abundant invertebrate fossil molds cemented by dolomite. The specimens of the deep infaunal bivalve, Panopea sp., occur together with bivalves representative of shallow infaunal species (Trachycardium sp. and Dosinia ponderosa [Gray, 1838]) and balanid barnacles, which are sessile encrusters. The Panopea specimens host compound molds evidencing an abundant encrusting fauna, including serpulids, ?foraminifera, bryozoans, and barnacles that colonized the inner surfaces of the valves before their final burial. We hypothesize that short-term, storm-related processes exhumed the living bivalves, resulting in a sedimentological concentration o...
Several aspects of the fascinating evolutionary history of toothed and baleen whales (Cetacea) ar... more Several aspects of the fascinating evolutionary history of toothed and baleen whales (Cetacea) are still to be clarified due to the fragmentation and discontinuity (in space and time) of the fossil record. Here we open a window on the past, describing a part of the extraordinary cetacean fossil assemblage deposited in a restricted interval of time (19–18 Ma) in the Chilcatay Formation (Peru). All the fossils here examined belong to the Platanistoidea clade as here redefined, a toothed whale group nowadays represented only by the Asian river dolphin Platanista gangetica. Two new genera and species, the hyper-longirostrine Ensidelphis riveroi and the squalodelphinid Furcacetus flexirostrum, are described together with new material referred to the squalodelphinid Notocetus vanbenedeni and fragmentary remains showing affinities with the platanistid Araeodelphis. Our cladistic analysis defines the new clade Platanidelphidi, sister-group to Allodelphinidae and including E. riveroi and the...
ABSTRACT In contrast to the suction-feeding, predominantly teuthophagous extant sperm whale, seve... more ABSTRACT In contrast to the suction-feeding, predominantly teuthophagous extant sperm whale, several Miocene physeteroids display proportionally larger teeth, deeply embedded in both upper and lower jaws. Together with other osteological features, these differences lead to the functional interpretation of these taxa as macroraptorial predators, using their teeth to capture and process large marine vertebrates. However, the assumption that strong forces applied to macroraptorial physeteroid teeth during powerful bites and contacts with bone material should result in major dental damage has not yet been tested. In the present work, we analyzed a large collection of physeteroid teeth with an enameled crown from the Miocene of the North Sea Basin. We especially focused on a set of 45 teeth of Scaldicetus caretti discovered in Antwerp (Belgium, southern North Sea Basin) and tentatively dated to the Tortonian (early late Miocene). Visual inspection and computed tomography (CT) scans revealed dental damage, including wear and breaks. The latter could be interpreted as chipping fractures, occurring along the crown, and vertical root fractures, observed along the apical part of the massive root. Chipping fractures are most likely due to contacts with hard material, whereas vertical root fractures may result from the application of strong and repetitive bite forces and/or contacts with hard material. Such results further support the interpretation of a series of Miocene physeteroids with proportionally large teeth as macroraptorial (rather than suction-feeding) top predators. Considering the size of the teeth of S. caretti, its most likely prey items were other large marine vertebrates.
Baleen whales (Mysticeti) are major ecosystem engineers, thanks to their enormous size and bulk f... more Baleen whales (Mysticeti) are major ecosystem engineers, thanks to their enormous size and bulk filter feeding strategy. Their signature gigantism is thought to be a relatively recent phenomenon, resulting from a Plio-Pleistocene mode shift in their body size evolution. Here, we report the largest whale fossil ever described: an Early Pleistocene (1.5–1.25 Ma) blue whale from Italy with an estimated body length of up to 26 m. Macroevolutionary modelling taking into account this specimen, as well as additional material from the Miocene of Peru, reveals that the proposed mode shift occurred either somewhat earlier, or perhaps not at all. Large-sized mysticetes comparable to most extant species have existed since at least the Late Miocene, suggesting a long-term impact on global marine ecosystems.
Coronuloid barnacles are epibionts of several marine vertebrates (including cetaceans and sea tur... more Coronuloid barnacles are epibionts of several marine vertebrates (including cetaceans and sea turtles) as well as invertebrates, and are assigned to two families of turtle barnacles (Chelonibiidae Pilsbry, 1916 and Platylepadidae Newman & Ross, 1976) and one family of whale barnacles (Coronulidae Leach, 1817). Chelonibiids and coronulids have a scanty, albeit significant fossil record extending back to the Eocene and Pliocene, respectively; in turn, the fossil record of platylepadids is limited to a single record from the Upper Pleistocene. Here we report on an isolated carinolateral compartment of Platylepas Gray, 1825, the type genus of the family, from Lower Pleistocene (Gelasian) epibathyal deposits exposed at Milazzo (Sicily, Italy). This specimen is here designated holotype of a new species, †Platylepas mediterranea sp. nov. We argue that, like most extant members of Platylepas, †P. mediterranea sp. nov. lived partially embedded in the skin of a sea turtle. This record of an e...
The upper Neogene Pisco Formation of Peru is known worldwide as one of the most significant Cenoz... more The upper Neogene Pisco Formation of Peru is known worldwide as one of the most significant Cenozoic marine vertebrate Konservatt-Lagerstätten, even featuring cetacean specimens that retain remains of soft tissues or stomach contents. Previous works showed that biomediated precipitation of dolomite concretions around large-sized decaying carcasses was one of the most relevant processes responsible for exceptional fossil preservation. In turn, little is known about the modes of fossilization of well-preserved small-sized vertebrates, which are rather common in the Pisco Formation, but mostly do not exhibit dolomite concretions. We report on a cetacean specimen, identified as belonging to the extinct short-snouted, small dolphin species Brachydelphis mazeasi (Pontoporiidae), preserved within a late Miocene sandy deposit at the site of Pampa Corre Viento. This specimen consists of a moderately disarticulated partial skeleton exhibiting well-mineralized bones; it is not enclosed within ...
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