J.W.F. Reumer

The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru

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 the largest raptorial predators and, to our knowledge, the biggest tetrapod bite ever found. The appearance of gigantic raptorial sperm whales in the fossil record coincides with a phase of diversification and size-range increase of the baleen-bearing mysticetes in the Miocene. We propose that Leviathan fed mostly on high-energy content medium-size baleen whales. As a top predator, together with the contemporaneous giant shark Carcharocles megalodon, it probably had a profound impact on the structuring of Miocene marine communities. The development of a vast supracranial basin in Leviathan, extending on the rostrum as in Physeter, might indicate the presence of an enlarged spermaceti organ in the former that is not associated with deep diving or obligatory suction feeding.

LATE PLEISTOCENE SURVIVAL OF THE SABER-TOOTHED CAT HOMOTHERIUM IN NORTHWESTERN EUROPE

Saber-toothed cats (Machairodontinae) were wide-spread, top predators of the Pleistocene terrestrial ecosystem. In Europe, they previously were known only from the early and middle Pleistocene (Adam, 1961; Turner and Anton, 1997), and their fossils are always extremely rare. The previous youngest record was from Steinheim a/d Murr, Germany, where an upper canine of Homotherium was found in a stratum dated to ca. 0.3 Ma (Adam, 1961). In this paper, we describe a well-preserved den- tary of Homotherium latidens dated by 14 C to be late Pleisto-

The evolution of shrews(Mammalia, Soricidae): A key role for humidity

Abstract The hypothesis is put forward that shrew evolution will have been favoured by relatively warm and humid palaeoclimates.To test this, First Appearance Dates (FADs) and Last Appearance Dates (LADs) of eleven different groups of shrews (subfamilies and tribes) are plotted against the absolute time-scale and American and European mammal zonations. Three periods can be discerned in which groups first appeared and that are here interpreted as periods of enhanced speciation. These periods are found in the Early Miocene (Ramblian in Europe, late Arikareean/early Hemingfordian in America, some 19–20 Ma ago), in the early late Miocene (the Vallesian in Europe and the Clarendonian in America, between 9–11 Ma ago), and in the Pliocene (Ruscinian in Europe, Blancan in America, between 6.0 and 2.4 Ma ago). Comparison of these three periods with published climatic curves shows that they coincide with periods of high relative humidity. It is concluded that the evolution of shrews is stimulated by humid paleoclimates.

The Taxonomical position of the Genus Paenelimnoecus Baudelot, 1972 (Mammalia: Soricidae): a resurrection of the Subfamily Allosoricinae

ABSTRACT The genus Paenelimnoecus Baudelot, 1972 and its species have in the course of time been assigned to the subfamilies Limnoecinae, Crocidurinae, Soricinae and Crocidosoricinae; it was still included in both latter subfamilies in the most recent literature. This enigmatic taxonomical situation is discussed. It is concluded that Paenelimnoecus belongs to the subfamily Allosoricinae Fejfar, 1966, which subfamily is here resurrected.

The stratigraphy of the Neogene-Quaternary succession in the southwest Netherlands from the Schelphoek borehole (42G4-11/42G0022) - a sequence-stratigraphic approach

We investigate the stratigraphy of Neogene and Quaternary intervals of the Schelphoek borehole (Schouwen, Zeeland, the Netherlands). The Breda Formation (Miocene-Zanclean) contains three sequences separated by hiatuses. The Oosterhout Formation (Zanclean-Piacenzian) contains at least two sequences. This formation is overlain by seven sequences of the Gelasian Maassluis Formation that almost certainly represent glacial cycles. The three lowermost sequences are provisionally assigned to the Praetiglian (MIS 96, MIS 98 and MIS 100). A large hiatus exists between the top of the Maassluis Formation and the base of the late Middle to Late Quaternary succession. Due to extensive in situ reworking of older strata (including fossils) at the base of several of the formations, their exact boundaries are difficult to establish. The Neogene succession in the Schelphoek borehole is compared to the stratigraphic successions in the Antwerp area to the south and the Dutch coastal area and continental platform to the north. Finally, the stratigraphic context of the Gelasian (‘Tiglian’) mammal fauna dredged from the bottom of a major tidal channel in the adjacent Oosterschelde is assessed by comparison with the Schelphoek borehole.

Extraordinary incidence of cervical ribs indicates vulnerable condition in Late Pleistocene mammoths

The number of cervical vertebrae in mammals is highly conserved at seven. We have shown that changes of this number are selected against due to a coupling with major congenital abnormalities (pleiotropic effects). Here we show that the incidence of abnormal cervical vertebral numbers in Late Pleistocene mammoths from the North Sea is high (33.3%) and approximately 10 times higher than that of extant elephants (3.6%). Abnormal numbers were due to the presence of large cervical ribs on the seventh vertebra, which we deduced from the presence of rib articulation facets on sixth (posterior side) and seventh (anterior side) cervical vertebrae. The incidence of abnormal cervical vertebral numbers in mammoths appears to be much higher than in other mammalian species, apart from exceptional sloths, manatees and dugongs and indicates a vulnerable condition. We argue that the increased incidence of cervical ribs in mammoths is probably caused by inbreeding and adverse conditions that impact early pregnancies in declining populations close to extinction in the Late Pleistocene.

The role of a proto-Schelde River in the genesis of the southwestern Netherlands, inferred from the Quaternary successions and fossils in Moriaanshoofd borehole (Zeeland, the Netherlands)

We investigated the Quaternary lithological succession and faunas in a borehole near Moriaanshoofd (Province of Zeeland, SW Netherlands), in order to improve our understanding of the depositional context of classical Gelasian mammal faunas from the region. The fossils mostly derive from the base of a fossil-rich interval between 31 m and 36.5 m below the surface, that was initially interpreted as a Middle or Late Pleistocene interglacial marine unit, but turned out to be a Late Quaternary fluvial unit with large amounts of reworked fossils and sediments. Eocene mollusc taxa pinpoint Randers (Belgium) as the source region for this river. Within the base of this paleo-Schelde River fossil material of various stratigraphic provenance became incorporated.

Hylopetes magistri, New Name for Hylopetes debruijni Reumer & Van Den Hoek Ostende, 2003, Preoccupied

In 2003, we published a new species of Hylopetes, H. debruijni, from the early Pleistocene locality of Tegelen, The Netherlands (Reumer and Van den Hoek Ostende, 2003). This publication appeared in a special volume in honor of Hans de Bruijn, which contained the proceedings of congress in Utrecht (17–19 May 2001) on the occasion of the 70th birthday of our esteemed colleague. While still in press, our publication was overtaken by a paper by Mein and Ginsburg (2002), who, unaware of our manuscript, also named a species of Hylopetes in honor of Hans de Bruijn. The type locality of H. debruijni Mein & Ginsburg, 2002, is the middle Miocene fissure filling La Grive M in France. The French material clearly represents a different species than the Dutch finds. Therefore, we conclude that, unfortunately, we published a name that was already preoccupied. Daxner-H¨ ock (2004) tentatively assigned the Dutch species to her new genus Neopetes, creating the new combination N. debruijni (Reumer and Van den Hoek Ostende, 2003). This, however, is of no consequence to the homonomy of the two species, as the ICZN specifically defines a primary homonym as identical species-group names for different taxa originally combined with the same generic name. As a primary homonym, H. debruijni Reumer & Van den Hoek Ostende, 2003, is permanently invalid (ICZN 1999:art 57.2). Therefore, we propose Hylopetes magistri new name for Hylopetes debruijni Reumer & Van den Hoek Ostende, 2003, preoccupied by Hylopetes debruijni Mein & Ginsburg, 2002. We consider assignation of the species magistri to the genus Neopetesas proposed by Daxner-H¨ ock (2004) premature, as this would first require direct comparison of the Dutch material to the type species of that genus. The specific name (magistri *Corresponding author. from Latin = of the master) mirrors our original intent to name the species after Hans de Bruijn, and stresses that the maestro has been instrumental in shaping the career of many palaeontologists, both in The Netherlands and abroad

New fossil insects from the Anisian (Lower to Middle Muschelkalk) from the Central European Basin (Germany and The Netherlands)

The Palaeozoic–Mesozoic transition is characterized not only by the most massive Phanerozoic mass extinction at the end of the Permian period, but also its extensive aftermath and a prolonged period of major biotal recovery during the succeeding Middle to Late Triassic. Particularly, Anisian insect species from units of the Lower to Middle Muschelkalk from the Central European Basin are rare. The specimens described here originated from the Anisian Wellenkalk facies (Lower Muschelkalk), Vossenveld Formation of the Winterswijk quarry, The Netherlands, and from the orbicularis Member (lowermost Middle Muschelkalk, Anisian) of Esperstedt near Querfurt (Saxony-Anhalt). Thus, the described insect remains from Winterwijk and Esperstedt expand our knowledge about Middle Triassic terrestrial arthropod communities and their palaeodiversity. A new species of Chauliodites (C. esperstedti sp. nov) is introduced.KurzfassungDer Übergang vom Paläozoikum zum Mesozoikum ist nicht nur durch eines der größten Massenaussterben des gesamten Phanerozoikums charakterisiert, sondern ist auch gekennzeichnet durch eines der zeitlich längsten Erholungsmuster terrestrischer Ökosysteme – vermutlich erst einsetzend während der mittleren bis späten Trias. Fundstellen für mitteltriassische Insekten, insbesondere aus Einheiten des unteren bis mittleren Muschelkalk, sind in Mitteleuropa gewöhnlich sehr selten. Die hier untersuchten Proben stammen vornehmlich von der Fundstelle Winterswijk, Niederlande (Vossenveld-Formation, Wellenkalk Fazies, Unterer Muschelkalk), wobei aus den ‘Orbicularisschichten’ (unterster Mittlerer Muschelkalk) von Esperstedt, nahe Querfurt (Sachsen-Anhalt), nur ein isolierter Fund beschrieben wird. Somit kommt den Fundstellen Winterwijk und Esperstedt eine besondere Bedeutung zu, weil sie hinsichtlich ihres gut erhaltenen und diversen Fossilinhalts bedeutende Fundorte für mitteltriassische Insektenreste darstellen und uns einen Einblick in die Ökologie und Ausbildung terrestrischer Lebensräume der mittleren Trias gewähren. Eine neue Art der Gattung Chauliodites (C. esperstedti sp. nov.) wird beschrieben.