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Holotype mandible and hyoid of Antwerpibalaena liberatlas (IRSNB M2325). A, mandibles in dorsal view. B, right mandible in medial view. C, symphyseal region of right mandible in medial view. D, fused basi-and thyrohyals in dorsal view.
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Right whales (Balaenidae) are the most distinctive family of extant baleen whales, thanks to their highly arched rostrum, tall lips and robust body shape. They are also the oldest, originating as much as 20 million years ago (Ma). Nevertheless, their fossil record is patchy and frequently understudied, obscuring their evolution. Here, we describe a...
Citations
... For the phylogenetic analysis, we used the same methodology and total evidence matrix from Duboys et al. [36] (updated version of the matrix from Marx and Fordyce (2015) [14] [38]. To the morphological data a maximum-likelihood model was assigned [39] and a gamma parameter (Mk + Γ), and the coding bias was set as "informative". ...
... To the morphological data a maximum-likelihood model was assigned [39] and a gamma parameter (Mk + Γ), and the coding bias was set as "informative". As in Duboys et al. [36], the analysis was set to run for 20 million generations, three separate runs with four chains each, sampling every 1000 generations and discarding the first 25% as burn-in. The trees obtained were summarized using SumTrees [40]. ...
... According to our phylogenetic analysis the Cetotheriidae clade is supported by the anteromedial portion of the palatines forming a well-developed medial crest (Character 21), the Contrary to Duboys et al [36], our analysis places the newly added Cephalotropis nectus and Cephalotropis coronatus in the most basal position of the Cetotheriidae clade, instead of Tiucetus rosae (Fig 24). The characters that are responsible for this shift are the narrow exposure of the vomer along the midline of the rostrum (Char. ...
Cetotheriidae is a family of baleen whales that went nearly extinct during the Pleistocene (excluding Caperea marginata). For a long time, the Cetotheriidae family has been seen as a problematic clade, but in the past two decades there have been various studies trying to resolve the phylogeny of this group. In 1831, Alexandre Vandelli described three cetotheriid skulls, found during a gold exploration at Adiça beach (Portugal). These specimens constituted the first Portuguese vertebrate fossils ever published in the literature. Another skull was added to the “Vandelli skulls” by Jacinto Pedro Gomes, in 1914, during a survey of the Museu Nacional de História Natural collections without giving information on the origin of this skull. In 1941, Remington Kellogg states that one of the original “Vandelli skulls” is no longer present in the Museu Nacional de História Natural collections. Until today, there is no information on how, or exactly when, the fourth skull and one of the original three “Vandelli skulls” appeared and disappeared, respectively. Since their discovery, all the attempts to describe these specimens were not based on direct observations and no comprehensive phylogenetic analysis have included the three skulls. Here we provide a detailed anatomic description, a new phylogenetic analysis and a palaeoecological reconstruction of these specimens, clarifying their relationships within the Cetotheriidae family and fostering the importance of these historical specimens to the modern comprehension of fossil whale evolution. In addition, our results support that Cephalotropis nectus is a valid species with an emended diagnosis. We also concluded that two specimens belong to a new genus, forming two new fossil species (new combinations).
... There are numerous phylogenetic hypotheses, which can be recognized as two types of Pelocetus calvertensis positions. Type A locates P. calvertensis basal to the Balaenopteridae (Lambert et al., 2017;Buono et al., 2017;De Muizon et al., 2019;Marx et al., 2019;de Lavigerie et al., 2020;FIGURE 3. Outlines of analyzed true baleen whale specimens. Numbers are given in Table 1 and Appendix 1. Abbreviations mean prey capture tactics (Sk: Skim, Mu: Multiple, Lu: Lunge) and prey types (Sm: Small, Bo: both large and small prey, La: Large, Un: Unknown). ...
... In this species, the dorsal transverse process is well developed and protruding, the medial border of the articular facet for the occipital condyle is medially concave and the space between the articular facets of the atlas is wide and rounded; all of these characters suggest that the holotype of Balaena etrusca should be assigned to the genus Eubalaena. The cervical vertebrae of Antwerpibalaena liberatlas (De Lavigerie et al., 2020) show Eubalaena-like characters in the medially concave medial border of the articular facet for the occipital condyle, in the presence of a wide and triangular space between the articular facets and in the presence of a neural process of the atlas. ...
... represents a unique case in the fossil record of balaenid whales as it is represented by a large portion of the postcranial skeleton. Unfortunately, the lack of the skull (with the exception of the dentaries) represented a major problem in the interpretation of the relationships of this whale for several years but the recent description of Archaeobalaena dosanko and Antwerpibalaena liberatlas by Tanaka et al. (2020) andDe Lavigerie et al. (2020), respectively, provided a new comparative context very useful to resolve the systematic affinities of C. valentinae n. gen., n. sp. These discoveries provided descriptions of cervical complexes and dentaries with new character combinations that allowed detailed comparisons with C. valentinae n. gen., n. sp. ...
... Morphological and pictorial data from True (1904), Omura (1958), Omura et al. (1969Omura et al. ( , 1971, Nishiwaki & Kasuya (1970) and Benke (1996) were included in that analysis that revealed a complex evolutionary process of the balaenid forelimb. De Lavigerie et al. (2020) showed that balaenids exhibit a diverse array of humeral, radial and ulnar morphologies that may be consistent with different swimming styles. In this respect, the presence of a well-developed teres fossa in C. valentinae n. gen., n. sp. ...
A partial skeleton of a Pliocene balaenid whale (Mammalia, Cetacea, Mysticeti) is described and compared to a large set of extant and fossil Balaenidae. The specimen (MCRE 232834) includes a jugal, both mandibular rami and part of the postcranial skeleton including several vertebrae, complete ribs, hyoid, pelvis, a single scapula and a single partial forelimb. The specimen was found at a site in the vicinity of the San Valentino Castle, about 16 km S from Reggio Emilia, close to the town of Castellarano, Emilia Romagna (northern Italy). Molluscs and foraminifers indicate a late Zanclean age for MCRE 232834, constrained between 3.8 and 3.6 Ma. A taphonomic analysis revealed that after death the individual sunk on the sea floor upside down and underwent a series of biostratinomic processes eventually leading to the collapse of the ribcage and to the disarticulation of the posterior thoracic, lumbar and caudal vertebrae, together with the loss of several skeletal elements including the skull. Shark teeth and encrusting molluscs demonstrate that the specimen was exploited by different organisms during its decay. The study of the skeleton revealed that MCRE 232834 shows an abruptly converging anterior ends of the mandibular rami, well-developed olecranon process in the ulna, peculiar morphology of the cervical vertebrae and enlarged attachment sites for axial muscles in the ribs. Based on the morphology of the cervical vertebrae, mandible and scapula, MCRE 232834 can be assigned to a new genus and species of the family Balaenidae, i.e., Charadrobalaena valentinae n. gen., n. sp., which is part of a primitive clade of balaenids that is the sister group of the crown balaenid whales. A functional analysis of the vertebral column revealed that it was able of comparatively faster and more agile swimming with respect to the extant balaenid species.
... Such phylogenetic hypotheses can be recognized in two types in this study. The two patterns differ in their placement of so-called cetotheres in the crown group (Type A [41][42][43][44][45][46][47]) or placing many 'cetotheres' basal to the Balaenidae (Type B [7,48]). ...
Baleen whales have lost their functional teeth and begun to use their baleen plates to feed on small prey. Modern baleen whales exhibit different types of feeding strategies, such as lunging, skimming and so on. The evolution of feeding strategy in the Chaeomysticeti is an important step in considering niche partitioning and diversification, feeding efficiency and gigantism, and evolution and extinction. This study analyses the rostrum morphology to test the hypothesis that specific rostral morphologies facilitate special feeding strategies, using modern species and their observed feeding strategies. By this means, the convergence of rostral morphology can be recognized in the closest groups in the morphospace. As a result, the two linages (Balaenidae and Caperea marginata) are recognized to have convergent rostral morphology. In addition, an early member of the Chaeomysticeti, Yamatocetus canaliculatus, and most fossil species are plotted in or close to the cluster of lunge feeders. The original feeding strategy of the Chaeomysticeti could be more similar to lunge feeding than to skim feeding. Fossil relatives of the two linages showing transitional conditions indicate that they shifted to skim feeding independently. The evolution of the feeding strategy of the Chaeomysticeti is possibly more complex than that was thought.
... In the Balaenidae, the distal border of the ulna is expanded at various degrees in different species. In particular, in Antwerpibalaena liberatlas, the posterior border of the distal end of the ulna is posteriorly protruded (Figure 25; see also images in [88]); this pattern is similar to that observed in the extant bowhead whale, Balaena mysticetus, in which the facet for the articulation with the humerus is flattened and largely destructured. In Eubalaena glacialis and E. australis (not included in Figure 25), the anterior border of the shaft of the ulna is anteriorly protruded, expanding the surface of the distal epiphysis of the ulna in a remarkable way ( Figure 25). ...
A review of the morphological patterns exhibited by all the main radiations of mysticete
(baleen whale) cetaceans provided a broad assessment of the fundamental morphological transformations that occurred in the transition to the Mysticeti clade. Skull and postcranial characters were illustrated, described and compared, and their distribution was mapped on a combined phylogeny in the search for morphological support for the principal mysticete clades (i.e., Mysticeti, Chaeomysticeti and Balaenomorpha). In particular, characters of the skull (rostrum, vertex, temporal fossa,
tympanic bulla and dentary) and the postcranial appendicular skeleton (scapula, humerus, radius and ulna) were all involved at different degrees in the process of morphological transformations leading to the modern-day mysticetes. Apart from a few typical characteristics of the rostrum that were already present in the earliest-diverging mysticetes (presence of lateral process of the maxilla, presence of multiple dorsal infraorbital foramina, thin lateral border of maxilla and presence of mesorostral groove), most of the other anatomical districts were unaffected by the transition so the earliest mysticetes show a number of archaeocete characters in the tympanic bulla, dentary and skull roof. The analysis of the whole dataset supported the hypothesis that the origin and evolution of mysticetes constituted a step-wise process and that the bauplan of the modern-day mysticetes was fully assembled at the level of the common ancestor of all Balaenomorpha.
... The Antwerp harbour region (Belgium) is well known for its thick and fossil-rich Pliocene successions (e.g. Vervoenen, 1995;Marquet, 1998Marquet, , 2002Marquet, , 2004Marquet, , 2005Marquet et al., 2009;Duboys de Lavigerie et al., 2020;Tsai et al., 2020). To the east these units become thin and discontinuous and often are affected by decalcification and reworking and the stratigraphic subdivision is not well understood (Marquet, 1980;Bisconti & Bosselaers, 2020;Bosselaers et al., 2004). ...
Detailed observations at a large temporary outcrop south of Antwerp International Airport (northern Belgium) reveal the complexity of a thin interval of fossil-rich Pliocene sediments found on top of the upper Miocene Diest Formation. Based on the lithological characteristics and mollusc faunas, several units were tentatively attributed to the Kattendijk Formation and the Luchtbal and Oorderen Members of the Lillo Formation. Concretions containing characteristic preserved molluscs dominated by large paired bivalves and that are informally known as the Broechem nodules were observed in situ between the Kattendijk Formation and Lillo Formation, and in reworked position in the base of the latter, indicating a late Early Pliocene age. The role of extensive reworking in the formation of Pliocene units is shown and implications for stratigraphic framework of Pliocene deposits from northern Belgium are discussed.
... The holotype of this species is fragmentary, and was only recognized as a right whale following the discovery of a more complete specimen from the same locality (Deméré and Pyenson, 2015). Together with Morenocetus, it is often considered basal to all other balaenids (Buono et al., 2017;Duboys de Lavigerie et al., 2020;Gol'din and Steeman, 2015), but the phylogenetic position of these early species remains in flux (e.g., Bisconti, 2005;Bisconti et al., 2017). ...
... Oldest amongst them is Eubalaena shinshuensis from Japan (Kimura, 2009), which at an estimated length of 12À13 m was twice as large as all of its predecessors (Buono et al., 2009(Buono et al., , 2017. Its appearance heralded a short-lived phase, lasting until about 3 Ma, during which balaenids diversified into a variety of species and body sizes: from the diminutive (6À8 m long) Balaenella brachyrhynus, Balaenotus insignis, Balaenula balaenopsis, and Balaenula astensis, to the medium-sized (9À10 m) Antwerpibalaena liberatlas, and the relatively large ( . 10 m) Balaena ricei and Eubalaena ianitrix (Bisconti, 2000(Bisconti, , 2005Bisconti et al., 2017;Duboys de Lavigerie et al., 2020;Trevisan, 1941;Van Beneden, 1880;Westgate and Whitmore, 2002). ...
... The phylogenetic relationships of most of these species remain poorly resolved. Some analyses variously intersperse them with living right whales (Bisconti, 2005;Bisconti et al., 2017;Churchill et al., 2012), whereas others support a closely knit crown group comprising only Balaena and Eubalaena (Buono et al., 2017;Duboys de Lavigerie et al., 2020). All studies agree, however, that bowhead whales emerged as part of this late Neogene "explosion" in balaenid diversity, giving rise to a lineage with at least three species: Balaena montalionis, B. ricei, and the extant Balaena mysticetus. ...
Bowhead whales are a member of Balaenidae (right whales), an ancient lineage stretching back at least 20 million years. Despite this long history, the early evolution of right whales remains obscured by a notoriously patchy fossil record. This pattern only changes about 7–6 million years ago (Ma), when balaenids suddenly appear around the globe in a variety of shapes and sizes. Bowhead whales arose during this radiation and initially shared the oceans with several smaller balaenids, some of them a mere 6–7 m long. This diverse assemblage abruptly declined with the onset of the ice ages about 3 Ma, which hit small baleen whales (including balaenids) especially hard. Thanks to their larger size, bowhead whales persisted, and eventually turned into polar specialists found exclusively in the Arctic.
A basal member of Balaenomorpha (Cetacea, Mysticeti), Persufflatius renefraaijeni, n. gen., n. sp., is described based on cranial material discovered in upper Miocene deposits of Liessel (the Netherlands). Thanks to the palynological analysis of an associated sediment sample, the specimen is dated from the late Tortonian (Dinozone SNS M14: c. 8.2-7.6 Ma). Our phylogenetic analysis recovers the new taxon at the base of the successful crown mysticete clade leading to modern rorquals. Though the holotype is
only partially preserved (it consists of the partial right side of the neurocranium), it provides new data on the cranial anatomy of these early relatives of extant rorquals, which are poorly represented in the global fossil record. Several skull parts (postglenoid process of the squamosal, base of the zygomatic process of the squamosal, the
anteromedioventral portion of the squamosal bone, and the exoccipital) show unusual swelling due to pachyostosis, giving the whole lateral basicranial region an inflated aspect.
An almost complete and partially articulated skeleton of an Early Pleistocene baleen whale is here described. The fossil, measuring 11 m in length, was discovered in the Calcarenite di Gravina Formation at Lama Lamasinata site (Bari, southern Italy) in 1968. The bifurcated first rib combined with other characters supports the identification of the fossil whale as a possible undescribed species of Balaenoptera (Mysticeti, Balaenopteridae), close to or nested in the B. borealis–B. edeni–B. ricei clade. However, the limited number of preserved diagnostic characters suggests a prudent assignment of the Bari whale to Balaenoptera sp. The associated molluscs suggest a mid-shelf setting deposition near to the boundary between infralittoral and circalittoral environments, probably 40-60 m deep. An associated Carcharodon carcharias tooth (the first case of a possible trophic interaction between white shark and cetaceans in the Pleistocene) and shark bite marks on a rib support the hypothesis that an early scavenger action prevented the rising of the whale carcass because of the removal of abdominal tissues and the consequent reduction of the decomposition gas accumulation. The occurrence of chemosymbiotic bivalves near the skeleton could testify the development of the sulphophilic stage during decay. Overall, the Bari whale skeleton and its associated fossil fauna represent the first well-documented case of Pleistocene whale fall community. The Bari specimen sheds new light on the diversity and disparity of the mysticete fauna in the Mediterranean Pleistocene also related to the geodynamic, palaeoclimatic and palaeoceanographic conditions that favoured upwelling events and nutrients supply into the southern Adriatic basin.
The evolution of gigantic body size represents a key to understand the ecological role of baleen whales in oceanic ecosystems. Many efforts have been devoted to the formulation of equations relating different body parts to total body length and mass in living and fossil mysticetes, mainly focusing on balaenopterid and balaenopterid-like mysticetes. Right whales (family Balaenidae) have a unique head-to-body length ratio, suggesting that their body proportions cannot be predicted effectively using equations based primarily on non-balaenid mysticetes. A new morphometric dataset of living and fossil balaenids is provided herein, and new regression equations allow one to predict the body length and mass of extinct species based on the expected head-to-body length ratio of extant balaenids. The reconstructed values are mapped on a new phylogenetic analysis of the Balaenidae, inferring body size and mass at ancestral nodes. The variations of body size and mass in Balaenidae since the early Miocene are reconstructed, revealing that: (1) a reduction in total body length occurred in the early Pliocene; (2) the origin of the gigantic body size in the bowhead whale (Balaena mysticetus) is probably related to invasion of the Arctic Ocean in the last 3 Myr; and (3) the origin of the gigantic body size in the right whales (genus Eubalaena) occurred since the latest Miocene, probably concomitant with pulses of nutrients sustaining large zooplankton populations. We suggest that the evolution of gigantism in Balaenidae occurred independently in two lineages and, probably, in response to different palaeoenvironmental drivers.
