[PaleoEntomology • 2022] Archaboilus musicus • High Acoustic Diversity and Behavioral Complexity of Katydids in the Mesozoic Soundscape

 

Archaboilus musicus Gu, Engel & Ren, 2012

in Xu, Wang, Wappler, Chen, ... et Engel, 2022.

  pnas.org/doi/10.1073/pnas.2210601119

Significance: 

Extinct animals usually had complex acoustic behavior, but fossils reveal little of these details. Here, we report the earliest insect ears and sound-producing system found in Mesozoic katydids. These katydids evolved unexpectedly high acoustic diversity. Our analysis shows that katydids are the earliest known animals to have evolved complex acoustic communication, acoustic niche partitioning, and high-frequency musical calls. Our results not only suggest that acoustic communication might have been an important driver for the early radiation of katydids but also support the hypothesis of the acoustic coevolution of mammals and katydids. These findings unveil acoustic behavioral complexity and evolutionary adaption amongst Mesozoic katydids and contribute to understanding the evolution of Mesozoic soundscape thus far mostly inaccessible from the paleontological record.

Abstract

Acoustic communication has played a key role in the evolution of a wide variety of vertebrates and insects. However, the reconstruction of ancient acoustic signals is challenging due to the extreme rarity of fossilized organs. Here, we report the earliest tympanal ears and sound-producing system (stridulatory apparatus) found in exceptionally preserved Mesozoic katydids. We present a database of the stridulatory apparatus and wing morphology of Mesozoic katydids and further calculate their probable singing frequencies and analyze the evolution of their acoustic communication. Our suite of analyses demonstrates that katydids evolved complex acoustic communication including mating signals, intermale communication, and directional hearing, at least by the Middle Jurassic. Additionally, katydids evolved a high diversity of singing frequencies including high-frequency musical calls, accompanied by acoustic niche partitioning at least by the Late Triassic, suggesting that acoustic communication might have been an important driver in the early radiation of these insects. The Early—Middle Jurassic katydid transition from Haglidae- to Prophalangopsidae-dominated faunas coincided with the diversification of derived mammalian clades and improvement of hearing in early mammals, supporting the hypothesis of the acoustic coevolution of mammals and katydids. Our findings not only highlight the ecological significance of insects in the Mesozoic soundscape but also contribute to our understanding of how acoustic communication has influenced animal evolution.

Ecological restoration of singing katydids from the Middle Jurassic Daohugou Konservat-Lagerstätte of China. 

Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences: NIGPAS

Chunpeng Xu, Bo Wang, Torsten Wappler, Jun Chen, Dmitry Kopylov, Yan Fang, Edmund A. Jarzembowski, Haichun Zhang and Michael S. Engel. 2022. High Acoustic Diversity and Behavioral Complexity of Katydids in the Mesozoic Soundscape. PNAS. 119 (51) e2210601119

  pnas.org/doi/10.1073/pnas.2210601119

 phys.org/news/2022-12-fossil-katydids-insights-evolution-mesozoic.html

[PaleoEntomology • 2023] Eomortoniellus handlirschi • An Eocene Insect could hear conspecific ultrasounds and bat echolocation

 Eomortoniellus handlirschi Zeuner, 1936

in Woodrow, Celiker & Montealegre-Z, 2023.

DOI: 10.1016/j.cub.2023.10.040  

 twitter.com/CharlieZoology

 Illustration by C. Woodrow.

Highlights: 

• A 44-million-year-old amber fossil katydid reveals exquisite ear preservation

• Biophysics of wings reveals this species utilized ultrasounds for communication

• Modeling of auditory range demonstrates tuning to male sexual signal, as well as to bat cries

• Ultrasound discrimination in insects was established by the Eocene

Summary: 

Hearing has evolved independently many times in the animal kingdom and is prominent in various insects and vertebrates for conspecific communication and predator detection. Among insects, katydid (Orthoptera: Tettigoniidae) ears are unique, as they have evolved outer, middle, and inner ear components, analogous in their biophysical principles to the mammalian ear. The katydid ear consists of two paired tympana located in each foreleg. These tympana receive sound externally on the tympanum surface (usually via pinnae) or internally via an ear canal (EC). The EC functions to capture conspecific calls and low frequencies, while the pinnae passively amplify higher-frequency ultrasounds including bat echolocation. Together, these outer ear components provide enhanced hearing sensitivity across a dynamic range of over 100 kHz. However, despite a growing understanding of the biophysics and function of the katydid ear, its precise emergence and evolutionary history remains elusive. Here, using microcomputed tomography (μCT) scanning, we recovered geometries of the outer ear components and wings of an exceptionally well-preserved katydid fossilized in Baltic amber (∼44 million years [Ma]). Using numerical and theoretical modeling of the wings, we show that this species was communicating at a peak frequency of 31.62 (± 2.27) kHz, and we demonstrate that the ear was biophysically tuned to this signal and to providing hearing at higher-frequency ultrasounds (>80 kHz), likely for enhanced predator detection. The results indicate that the evolution of the unique ear of the katydid, with its broadband ultrasonic sensitivity and analogous biophysical properties to the ears of mammals, emerged in the Eocene.

Keywords: palaeoentomology, fossil, bioacoustics, predation, arms race, hearing, finite element analysis, bats, eavesdropping, echolocation

 Remarkable preservation of the ears and wings of Eomortoniellus handlirschi provides insights into the evolution of katydid communication
 (A) E. handlirschi male habitus μCT reconstruction showing ECs. (B) View of the anterior tympanum and external ear structures through amber, with dotted line indicating cross-section in (C). (C) μCT cross-section of the foretibial ear. (D) Forewings and associated sound-production regions through amber. (E) Illustrated diagram of (C). (F) Illustrated diagram of (D).

(G) Reconstruction of E. handlirschi moments before encapsulation in tree resins.

Abbreviations are as follows: ap, anterior pinna; at, anterior tracheal branch; atm, anterior tympanum; c, cuticle; ca, crista acustica; dw, dorsal wall; h1–3, harp regions; m, mirror; pp, posterior pinna; pt, posterior tracheal branch; ptm, posterior tympanum; s, septum; v, volume.

 Illustration in (F) modified from Gorochov (2010) Illustrations in (E) and (G) by C Woodrow.

Eomortoniellus handlirschi Zeuner, 1936

 Charlie Woodrow, Emine Celiker and Fernando Montealegre-Z. 2023. An Eocene Insect could hear conspecific ultrasounds and bat echolocation. Current Biology. In Press. DOI: 10.1016/j.cub.2023.10.040

  twitter.com/CharlieZoology/status/1724094436273992101

[PaleoMammalogy • 2023] Vielasia sigei • A 50-million-year-old, three-dimensionally preserved Bat Skull supports an early Origin for Modern Echolocation

Vielasia sigei

Hand, Maugoust, Beck & Orliac, 2023

DOI: 10.1016/j.cub.2023.09.043

 

Highlights

• A new bat species is described from a 50-million-year-old cave deposit in France

• Its well-preserved fossils include the oldest uncrushed skull of a bat yet known

• This stem bat appears to have been capable of advanced (laryngeal) echolocation

• The fossils suggest that advanced echolocation predates the crown bat radiation

Summary

Bats are among the most recognizable, numerous, and widespread of all mammals. But much of their fossil record is missing, and bat origins remain poorly understood, as do the relationships of early to modern bats. Here, we describe a new early Eocene bat that helps bridge the gap between archaic stem bats and the hyperdiverse modern bat radiation of more than 1,460 living species. Recovered from ∼50 million-year-old cave sediments in the Quercy Phosphorites of southwestern France, Vielasia sigei’s remains include a near-complete, three-dimensionally preserved skull—the oldest uncrushed bat cranium yet found. Phylogenetic analyses of a 2,665 craniodental character matrix, with and without 36.8 kb of DNA sequence data, place Vielasia outside modern bats, with total evidence tip-dating placing it sister to the crown clade. Vielasia retains the archaic dentition and skeletal features typical of early Eocene bats, but its inner ear shows specializations found in modern echolocating bats. These features, which include a petrosal only loosely attached to the basicranium, an expanded cochlea representing ∼25% basicranial width, and a long basilar membrane, collectively suggest that the kind of laryngeal echolocation used by most modern bats predates the crown radiation. At least 23 individuals of V. sigei are preserved together in a limestone cave deposit, indicating that cave roosting behavior had evolved in bats by the end of the early Eocene; this period saw the beginning of significant global climate cooling that may have been an evolutionary driver for bats to first congregate in caves.

 

Keywords: bat, Eocene, France, fossil, skull, echolocation, cochlea, paleontology, phylogeny, cave dwelling

Systematic paleontology

Order Chiroptera Blumenbach, 1779

Family indeterminate

Vielasia gen. nov.

 

Generic etymology. From the type locality Vielase.

Geological setting. Vielase is among the oldest fossil deposits identified in the karstic terrane of the Quercy Phosphorites, southwestern France.50,56,57 The Vielase fossils were extracted from a russet-colored bone breccia and a light-colored limestone by acid processing.50,58 More than 400 bat specimens referable to Vielasia sigei were recovered, with the most complete specimens (including the holotype cranium UM-VIE-250) being extracted from the light-colored limestone (B. Marandat, personal communication). Taphonomically, these bat fossils are consistent with in situ accumulation in a cave;59,60 the remains are well preserved but dissociated and include 3D-preserved cranial and postcranial specimens representing multiple individuals, with teeth and bones unworn and without rounding or size filtering indicative of transport, nor evidence of digestion or accumulation by (e.g.) predatory birds. Much rarer rodent, primate, and carnivorous mammal fossils recovered from the site50 have been used to biocorrelate the deposit as reference level MP10 in the European Palaeogene mammal biostratigraphy.49,50,51,52

Vielasia sigei sp. nov. 

Synonymy. Archaeonycteridae gen. et sp. indet. in Sigé58 and in Legendre et al. (see figure 7)50

Suzanne J. Hand, Jacob Maugoust, Robin M.D. Beck and Maeva J. Orliac. 2023. A 50-million-year-old, three-dimensionally preserved Bat Skull supports an early Origin for Modern Echolocation.  Current Biology. In Press, DOI: 10.1016/j.cub.2023.09.043

   phys.org/news/2023-10-fossilized-skull-vital-piece-evolution.html

[Mammalogy • 2021] Histiotus mochica • A New Species of Histiotus Gervais, 1856 (Chiroptera, Vespertilionidae), from the Pacific Coast of Northern Peru

Histiotus mochica

 Velazco, Almeida, Cláudio, Giménez & Giannini, 2021

DOI: 10.1206/3979.1 

 facebook.com/PaulVelazco

 arcadia.edu

Abstract 

The Pacific coastal desert of Peru harbors a unique bat fauna, including narrowly endemic taxa adapted to arid environments. This region was also the setting where several pre-Incan civilizations flourished. The Moche culture (100–850 CE) was one of those, with a rich and diverse material culture that included strikingly realistic ceramic representations of the regional flora and fauna. In particular, one Mochica pottery vessel is in the form of a bat that, based on external characteristics (large pinnae and tragus, pinnae connected by high band of membrane across the forehead, and lack of noseleaf), clearly represents an individual of the vespertilionid genus Histiotus. The morphological characteristics observed in this vessel, in addition to the area of influence of the Moche culture, suggests that this vessel depicts a species previously unknown to science that we describe here as new on the basis of two specimens obtained in 2012 in the Peruvian department of Piura. Our new species, Histiotus mochica, can be distinguished from other congeners by having unicolored dorsal fur, medial lobes of pinnae greater than 9.5 mm wide, and a well-developed (>4.3 mm high) transverse band of skin connecting the pinnae. Cytochrome b sequence data indicate that the new species is sister to H. humboldti from the Andes of Colombia and northern Ecuador. The new species is a medium-sized Histiotus that clusters with H. laephotis, H. velatus, and with small specimens of H. montanus in our multivariate analyses. With the description of H. mochica, the diversity of the genus increases to 11 species. We provide a key based on external characters of all known species of Histiotus.

 

  Histiotus mochica

Paúl M. Velazco, Francisca Cunha Almeida, Vinícius C. Cláudio, Analía L. Giménez and Norberto P. Giannini. 2021. A New Species of Histiotus Gervais, 1856 (Chiroptera, Vespertilionidae), from the Pacific Coast of Northern Peru. American Museum Novitates. (3979); 1-30. DOI: 10.1206/3979.1

  facebook.com/groups/192466010712/permalink/10166490838540713/

digitallibrary.amnh.org/handle/2246/9

Dr. Velazco Discovers Species of Bat in Northern Peru Connected to Ancient Moche Culture   

arcadia.edu/story/dr-velazco-discovers-species-bat-northern-peru-connected-ancient-moche-culture

[Mammalogy • 2021] A New Species of Long-eared Brown Bat of the Genus Histiotus (Chiroptera) and the Revalidation of Histiotus colombiae

 

Histiotus cadenai Rodríguez-Posada, Ramírez-Chaves & Morales-Martínez, 

in Rodríguez-Posada, Morales-Martínez, ... et Calderón-Acevedo, 2021. 

DOI: 10.15446/caldasia.v43n2.85424 

  twitter.com/DMMoralesMar 

The South American bats of the genus Histiotus comprises between four and eight species, but their taxonomy has been controversial and the limits between species and their distribution are not well understood. In Colombia, Histiotus humboldti and H. montanus colombiae have been recorded, but undescribed species has been suggested. We evaluated the species richness and distribution of Colombian Histiotus using morphological, molecular, and acoustic traits. Our results evidence three species in Colombia, the two previously recorded taxa and a new species from the Cordillera Central of Colombia and northern Ecuador that we describe here. We also revalidated H. colombiae as a full species. H. humboldti is widely distributed in the Colombian and Ecuadorean Andes and can be sympatric with the other two species. H. colombiae is restricted to the Colombian Cordillera Oriental. Finally, we highlight the potential hidden diversity within Histiotus in the Peruvian and Bolivian Andes, the need to resolve the evolutionary relationships of the genus, and its implications to the understanding of the processes that have structured the Andean mammal fauna.

Keywords: Andes, Cytochrome b, echolocation calls, morphometry, Vespertilionidae

 

Histiotus cadenai Rodríguez-Posada, Ramírez-Chaves and Morales-Martínez, new species 

Cadena´s Long-Eared bat.

Etymology. The species epithet honors the Colombian pioneering mammalogist Alberto Cadena-García. He trained several generations of researchers currently working around the world on topics such as biology and conservation of mammals, continuing his legacy for new generations of biologists.

 

Miguel E. Rodríguez-Posada, Darwin M. Morales-Martínez, Héctor E. Ramírez-Chaves, Daniela Martínez-Medina and Camilo A. Calderón-Acevedo. 2021. Una nueva especie de murciélago pardo de orejas largas del género Histiotus (Chiroptera) y revalidación de Histiotus colombiae [A New Species of Long-eared Brown Bat of the Genus Histiotus (Chiroptera) and the Revalidation of Histiotus colombiae]. CALDASIA. 43(2) DOI: 10.15446/caldasia.v43n2.85424

Researchgate.net/publication/349725085_A_new_species_of_Histiotus_and_the_revalidation_of_Histiotus_colombiae

  twitter.com/DMMoralesMar/status/1367285893153894401

 twitter.com/CamiloAndresAC/status/1367293198381572103

  facebook.com/IZBDLab/posts/296583985225450

Los murciélagos suramericanos del género Histiotus comprenden entre cuatro y ocho especies, pero su taxonomía ha sido controversial y los límites entre sus especies y sus áreas de distribución no son bien entendidos. En Colombia, se han registrado a Histiotus humboldti y a H. montanus colombiae, pero se ha propuesto que hay especies por descubrir. Evaluamos la riqueza de especies de murciélagos Histiotus colombianos incluyendo caracteres morfológicos, moleculares y acústicos. Nuestros resultados evidencian la presencia de tres especies en Colombia, los dos taxones previamente registrados y una especie nueva de la Cordillera Central de Colombia y el norte de Ecuador que describimos aquí. Además, revalidamos H. colombiae a nivel de especie. H. humboldti presenta la distribución más amplia en los Andes colombianos y ecuatorianos, y puede estar en simpatría con las otras dos especies. H. colombiae es sólo conocida de la Cordillera Oriental de Colombia. Finalmente, resaltamos la diversidad potencial no descrita de Histiotus en los Andes peruanos y bolivianos, la necesidad de resolver las relaciones evolutivas del género y sus implicaciones en el entendimiento de los procesos que han estructurado la fauna Andina de mamíferos.

Palabras clave: Andes, Vespertilionidae, Citocromo b, ecolocalización, Morfometría 

[Mammalogy • 2020] The Masked Seducers: Lek Courtship Behavior in the Wrinkle-faced Bat Centurio senex (Phyllostomidae)

Centurio senex Gray, 1842

in Rodríguez-Herrera, Sánchez-Calderón, Madrigal-Elizondo, et al., 2020.

  DOI: 10.1371/journal.pone.0241063 

Abstract

Centurio senex is an iconic bat characterized by a facial morphology deviating far from all other New World Leaf Nosed Bats (Phyllostomidae). The species has a bizarrely wrinkled face and lacks the characteristic nose leaf. Throughout its distribution from Mexico to Northern South America the species is most of the time rarely captured and only scarce information on its behavior and natural history is available. Centurio senex is frugivorous and one of the few bats documented to consume also hard seeds. Interestingly, the species shows a distinct sexual dimorphism: Adult males have more pronounced facial wrinkles than females and a fold of skin under the chin that can be raised in style of a face mask. We report the first observations on echolocation and mating behavior of Centurio senex, including synchronized audio and video recordings from an aggregation of males in Costa Rica. Over a period of 6 weeks we located a total of 53 perches, where during the first half of the night males were hanging with raised facial masks at a mean height of 2.35 m. Most of the time, the males moved just their wing tips, and spontaneously vocalized in the ultrasound range. Approaches of other individuals resulted in the perching male beating its wings and emitting a very loud, low frequency whistling call. Following such an encounter we recorded a copulation event. The observed aggregation of adult C. senex males is consistent with lek courtship, a behavior described from only few other bat species.

Fig 5. Field photographs
a) Centurio senex male with raised facial mask; b) male with lowered facial mask;
c) perching male being approached by another individual; d) detail of same perching male during the approach, just before emitting a whistle sequence.

Conclusion: 

Our study summarizes the first behavioral data from a lek of Centurio senex males, observed over a period of almost 6 weeks at a Costa Rican highland forest site. The exclusively male bats used stable perches and showed distinct behavioral patterns including an acoustic signaling with stereotypical elements that might serve to attract females and perhaps also to signal male quality. Perching animals were regularly approached by other individuals and in one case such an encounter was followed by a copulation. Males often spent several hours on the perch without leaving and abandoned it only after midnight. This endurance left males with only half of the night time for foraging, so the time spent on the perch is a significant energetic investment and could be a honest signal for male quality. Our study has some obvious shortcomings. While we were extremely lucky to obtain the first observations on the behavior of this interesting species we deliberately refrained from mist-netting bats in order not to scare the animals away from our study site. The downside of this cautious approach is, however, that we still lack essential data, such as the sex ratio at the site, the body condition of individual males or the identity of all visitors. In this context, it would also be highly interesting to assess potential olfactory signals of the perching males, perhaps in the facial region. Hopefully, the encounter of a future lek of Centurio senex will allow us to close some of the current gaps in the knowledge on the behavior of one of the most iconic bats of the Neotropics.

Bernal Rodríguez-Herrera, Ricardo Sánchez-Calderón, Victor Madrigal-Elizondo, Paulina Rodríguez, Jairo Villalobos, Esteban Hernández, Daniel Zamora-Mejías, Gloria Gessinger and Marco Tschapka. 2020. The Masked Seducers: Lek Courtship Behavior in the Wrinkle-faced Bat Centurio senex (Phyllostomidae). PLoS ONE. 15(11): e0241063. DOI: 10.1371/journal.pone.0241063

Wrinkle-faced male bats lower face masks to copulate

The first behavioral observations of wrinkle-faced bats in their natural habitat reveal that this elusive species uses the rarest form of bat courtship behavior, according to a new study.

 sciencedaily.com/releases/2020/11/201111153113.htm

     

[Mammalogy • 2020] The Evolution of Flight in Bats: A Novel Hypothesis

Summary of the interdigital webbing hypothesis, showing the proposed evolutionary trajectories of the Yangochiroptera, Rhinolophoidea and Megachiroptera. 

in Anderson & Ruxton, 2020.

 DOI: 10.1111/mam.12211

Abstract

Bats (order Chiroptera) are the only mammals capable of powered flight, and this may be an important factor behind their rapid diversification into the over 1400 species that exist today – around a quarter of all mammalian species. Though flight in bats has been extensively studied, the evolutionary history of the ability to fly in the chiropterans remains unclear.

We provide an updated synthesis of current understanding of the mechanics of flight in bats (from skeleton to metabolism), its relation to echolocation, and where previously articulated evolutionary hypotheses for the development of flight in bats stand following recent empirical advances. We consider the gliding model, and the echolocation‐first, flight‐first, tandem development, and diurnal frugivore hypotheses. In the light of the recently published description of the web‐winged dinosaur Ambopteryx longibrachium, we draw together all the current evidence into a novel hypothesis.

We present the interdigital webbing hypothesis: the ancestral bat exhibited interdigital webbing prior to powered flight ability, and the Yangochiroptera, Pteropodidae, and Rhinolophoidea evolved into their current forms along parallel trajectories from this common ancestor. Thus, we suggest that powered flight may have evolved multiple times within the Chiroptera and that similarity in wing morphology in different lineages is driven by convergence from a common ancestor with interdigital webbing.

Keywords: bats, Chiroptera, echolocation, evolution of flight, interdigital webbing, pterosaurs, Scansoriopterygidae

Fig. 1:  Phylogenetic groupings of chiropterans, showing the relevant subdivisions of the Chiroptera into the Megachiroptera/Microchiroptera and the Yinpterochiroptera/Yangochiroptera.

Fig. 2: Summary of the interdigital webbing hypothesis, showing the proposed evolutionary trajectories of the Yangochiroptera, Rhinolophoidea and Megachiroptera.

CONCLUSION: 

The ability of some vertebrates to take flight has been studied in a range of scientific disciplines, and yet the evolutionary journey of chiropterans from small arboreal mammals to the adept flyers we know today has never been laid out definitively. The story is inherently more complex than that of other vertebrate flyers such as birds, thanks to the close coupling of flight and echolocation in many bat species, and the evolution of flight in bats cannot be uncovered without taking this into account. With advances in molecular analyses, the phylogenetic tree of chiropterans is becoming clearer; the Rhinolophoidea is emerging as unique, not only in morphology and behaviour, but also in phylogeny.

Many hypotheses for the evolution of flight in bats remain viable, but we present a novel hypothesis which synthesises current understanding of chiropteran flight, phylogeny and evolution: that the ancestral bat exhibited interdigital webbing, and that the Yangochiroptera, Pteropodidae, and Rhinolophoidea evolved into their current forms along parallel trajectories from this common ancestor. Drawing on comparisons from the vertebrates, and in the light of the recently published description of the membrane‐winged dinosaur Ambopteryx longibrachium, this interdigital webbing hypothesis provides a biologically satisfying narrative for the evolution of flight in bats, from arboreal mammals to the fastest‐flying vertebrates that we know of. In comparison with some previous hypotheses, this novel hypothesis may be less parsimonious, but we feel it offers the best fit to currently available empirical evidence. Further evidence could strengthen support for this hypothesis, or falsify it.

 

Sophia C. Anderson and Graeme D. Ruxton. 2020. The Evolution of Flight in Bats: A Novel Hypothesis. Mammal Review. DOI: 10.1111/mam.12211

[Mammalogy • 2020] Philippine Bats of the Genus Kerivoula (Chiroptera: Vespertilionidae): Overview and Assessment of Variation in K. pellucida and K. whiteheadi

Kerivoula pellucida  Waterhouse 1854

Kerivoula whiteheadi Thomas, 1894

in Sedlock, Heaney, Balete & Ruedi, 2020. 

DOI: 10.11646/zootaxa.4755.3.2

Abstract

Bats of the genus Kerivoula (Mammalia, Chiroptera) are widespread in the Philippines with four reported species, but have been poorly known due to a paucity of specimens. We provide the first molecular phylogeny for Philippine Kerivoula, which supports the existence of four distinct clades that we treat as species (K. hardwickii, K. papillosa, K. pellucida, and K. whiteheadi); these four overlap broadly geographically. Each of these may be recognized on the basis of cytochrome b sequences and external and craniodental morphology. Detailed examination of K. pellucida shows little geographic differentiation within the Philippines, but they differ subtly from those on the Sunda Shelf. We consider K. whiteheadi to be composed of four recognizable clades, each restricted to a geographic region within the Philippines. We consider K. bicolor, from peninsular Thailand, and K. pusilla, from Borneo, to be distinct from K. whiteheadi. Our data indicate the presence of two species within the Philippines currently lumped as K. hardwickii; further study of these is needed. A calibrated phylogeny suggests that Kerivoula began arriving in the Philippines about 10 MYA, with each of the four current lineages arriving independently.

 Keywords: Mammalia, biogeography, cytochrome b, echolocation, ecology, morphology, phylogeny, Southeast Asia

FIGURE 5. Photograph composite of Kerivoula pellucida showing the nearly translucent wing membranes (A), pelage color, and ears with tapered tragus (B), membrane attachment on foot and membrane with male gland (C).

 A: Bohol I. (no voucher); B–C: FMNH 205817, Cebu I. 

FIGURE 12. Photo composite of Kerivoula whiteheadi venter with membrane attachment to foot and bicolor pelage (A), dorsum with fur-lined legs and feet (B), head with pointed tragus and high forehead (C).

 A and C: FMNH 205818, Cebu I.; B: FMNH 191330, Luzon I. 

Kerivoula pellucida Waterhouse 1854

Distribution. Borneo, Java, the Malay Peninsula, the Philippines (Cebu, Jolo, Mindanao, Mindoro, and Palawan), and Siberut (Fig. 2; see also Corbet & Hill 1992: 154).

Kerivoula whiteheadi Thomas, 1894

Distribution. Endemic to the Philippines (Bohol, Camguin Norte, Cebu, Lubang, Luzon, Mindanao, Mindoro, Palawan, Sicogon, Siquijor and Tumaguin; Fig. 2). The type locality “Molino” probably refers to a currently nonexistent village on the east bank of the Ilagan River downstream from the city of San Mariano (M. van Weerd, pers. com., 6 May 2019).

Jodi L. Sedlock, Lawrence R. Heaney, Danilo S. Balete and Manuel Ruedi. 2020. Philippine Bats of the Genus Kerivoula (Chiroptera: Vespertilionidae): Overview and Assessment of Variation in K. pellucida and K. whiteheadi. Zootaxa. 4755(3); 454–490. DOI: 10.11646/zootaxa.4755.3.2

[Ecology • 2018] The Evolution of Foraging Capacity and Gigantism in Cetaceans

Different marine vertebrates exploiting a bait ball of forage fish.

in Goldbogen & Madsen, 2018.

  DOI: 10.1242/jeb.166033 

twitter.com/GoldbogenLab 

ABSTRACT

The extant diversity and rich fossil record of cetaceans provides an extraordinary evolutionary context for investigating the relationship between form, function and ecology. The transition from terrestrial to marine ecosystems is associated with a complex suite of morphological and physiological adaptations that were required for a fully aquatic mammalian life history. Two specific functional innovations that characterize the two great clades of cetaceans, echolocation in toothed whales (Odontoceti) and filter feeding in baleen whales (Mysticeti), provide a powerful comparative framework for integrative studies. Both clades exhibit gigantism in multiple species, but we posit that large body size may have evolved for different reasons and in response to different ecosystem conditions. Although these foraging adaptations have been studied using a combination of experimental and tagging studies, the precise functional drivers and consequences of morphological change within and among these lineages remain less understood. Future studies that focus at the interface of physiology, ecology and paleontology will help elucidate how cetaceans became the largest predators in aquatic ecosystems worldwide.

Keywords: Scaling, Odontocetes, Mysticetes, Diving, Filter feeding, Echolocation

Fig. 1. Illustration of different marine vertebrates exploiting a bait ball of forage fish.
Among these species are many particulate feeders (e.g. cormorants, sea lions and dolphins), those that are largely limited to capturing one prey at a time. This contrasts with bulk filter feeding, characterized by the engulfment of large numbers of prey in a single mouthful, here represented by a humpback whale.

 Illustration by Alex Boersma.

J. A. Goldbogen and P. T. Madsen. 2018. The Evolution of Foraging Capacity and Gigantism in Cetaceans. Journal of Experimental Biology. 221: jeb166033. DOI: 10.1242/jeb.166033 

twitter.com/GoldbogenLab/status/1006556588990070784

[Mammalogy • 2017] Typhlomys chapensis • A Blind Climber: The First Evidence of Ultrasonic Echolocation in Arboreal Mammals

Typhlomys chapensis Osgood, 1932

Panyutina, Kuznetsov, Volodin, et al., 2017.

DOI: 10.1111/1749-4877.12249 

Abstract

 The means of orientation is studied in the Vietnamese pygmy dormouse Typhlomys chapensis, a poorly known enigmatic semi-fossorial semi-arboreal rodent. Data on eye structure are presented, which prove that Typhlomys (translated as "the blind mouse") is incapable of object vision – the retina is folded and retains no more than 2 500 ganglion cells in the focal plane, and the optic nerve is subject to gliosis. Hence, Typhlomys has no other means for rapid long-range orientation among tree branches other than echolocation. Ultrasonic vocalization recordings at the frequency range of 50-100 kHz support this hypothesis. The vocalizations are represented by bouts of up to 7 more or less evenly-spaced and uniform frequency-modulated sweep-like pulses in rapid succession. Structurally, these sweeps are similar to frequency-modulated ultrasonic echolocation calls of some bat species, but they are too faint to be revealed with a common bat detector. When recording video simultaneously with the ultrasonic audio, a significantly greater pulse rate during locomotion compared to that of resting animals has been demonstrated. Our findings of locomotion-associated ultrasonic vocalization in a fast-climbing but weakly-sighted small mammal ecotype add support to the "echolocation-first theory" of pre-flight origin of echolocation in bats.

 Key words: ultrasonic echolocation, locomotor behaviour, arboreal locomotion, reduced eyes, Typhlomys, Rodentia

Figure 1 Vietnamese pygmy dormouse Typhlomys chapensis. Its reduced eyes are reflected in the generic name, which means “the blind mouse.”

Concluding remarks. The major limitations of our study were the small number of live individuals to experiment with and the poor quality of dead specimens for histology. This is due to the extreme rarity of the Vietnamese pygmy dormouse, or "blind mouse" in nature. That is why our conclusions, though rather convincing, are still preliminary. Additional research is required to describe in detail the acoustic patterns of ultrasonic pulses and bouts in Typhlomys and to compare them with the known acoustics of bats and with non-echolocation ultrasonic calls of other rodents. A remaining question is the mechanism of signal production – is it located in the larynx? and is the animal entirely incapable to communicate in the human-audible range indeed? It will be of interest to investigate the degree of eye degeneration and development of echolocation in a closely related and very similar species, the Chinese pygmy dormouse – Typhlomys cinereus.

Aleksandra A. Panyutina, Alexander N. Kuznetsov, Ilya A. Volodin, Alexey V. Abramov and Irina B. Soldatova. 2017. A Blind Climber: The First Evidence of Ultrasonic Echolocation in Arboreal Mammals. Integrative Zoology. 12(2); 172–184.  DOI: 10.1111/1749-4877.12249

ResearchGate.net/publication/311760839_A_blind_climber_The_first_evidence_of_ultrasonic_echolocation_in_arboreal_mammals

 Video: Blind mouse navigates like a bat sciencemag.org/news/2017/01/video-blind-mouse-navigates-bat

Blind climber science.sciencemag.org/content/355/6322/258.5

An echolocating dormouse could reveal the origins of one of nature's coolest superpowers http://po.st/YfQ1MK  @SmithsonianMag

Rare rodent is the first tree-climbing mammal known to echolocate like a bat | MNN  mnn.com/earth-matters/animals/stories/rare-rodent-first-tree-climbing-mammal-known-echolocate-bat

[PaleoMammalogy • 2017] New Records of the Dolphin Albertocetus meffordorum (Odontoceti: Xenorophidae) from the lower Oligocene of South Carolina: Encephalization, Sensory Anatomy, Postcranial Morphology, and Ontogeny of early Odontocetes

Albertocetus meffordorum   Uhen, 2008 

Boessenecker, Ahmed & Geisler, 2017

DOI: 10.1371/journal.pone.0186476 

Abstract

We report five new specimens of xenorophid dolphins from North and South Carolina. Four of the specimens represent the xenorophid Albertocetus meffordorum, previously only known from the holotype skull. The other is a fragmentary petrosal from the upper Oligocene Belgrade Formation that we refer to Echovenator sp, indicating at least two xenorophids from that unit. Two of the Albertocetus meffordorum specimens are from the lower Oligocene Ashley Formation: 1) a partial skeleton with neurocranium, fragmentary mandible, ribs, vertebrae, and chevrons, and 2) an isolated braincase. The partial vertebral column indicates that Albertocetus retained the ancestral morphology and locomotory capabilities of basilosaurid archaeocetes, toothed mysticetes, and physeteroids, and caudal vertebrae that are as wide as tall suggest that the caudal peduncle, which occurs in all extant Cetacea, was either wide or lacking. CT data from the isolated braincase were used to generate a digital endocast of the cranial cavity. The estimated EQ of this specimen is relatively high for an Oligocene odontocete, and other aspects of the brain, such as its anteroposterior length and relative size of the temporal lobe, are intermediate in morphology between those of extant cetaceans and terrestrial artiodactyls. Ethmoturbinals are also preserved, and are similar in morphology and number to those described for the Miocene odontocete Squalodon. These fossils extend the temporal range of Albertocetus meffordorum into the early Oligocene, its geographic range into South Carolina, and expand our paleobiological understanding of the Xenorophidae.

Fig 1. Locality map of occurrences of Albertocetus meffordorum in North and South Carolina. (A) and a geologic map of Charleston, South Carolina (B), skeletal reconstruction of Albertocetus meffordorum with preserved elements in red (C), generalized stratigraphy at Belgrade Quarry (D)  and generalized Paleogene stratigraphy of the Charleston area (E). Gray in geologic map denotes Ashley Formation and black denotes Chandler Bridge Formation. 

Systematic paleontology

Cetacea Brisson, 1762

Pelagiceti Uhen, 2008

Odontoceti Flower, 1867

Xenorophidae Uhen, 2008

Albertocetus Uhen, 2008

Albertocetus meffordorum Uhen, 2008

.....

Conclusions

1. New odontocete specimens from the lower Oligocene Ashley Formation of South Carolina include an isolated cranium and a partial skeleton including incomplete cranium with petrotympanics and fragmentary mandible, cervical, thoracic, lumbar, and caudal vertebrae, ribs, and a chevron. These specimens extend the range of Albertocetus meffordorum into the early Oligocene.

2. Well-preserved petrosals permit more refined identification of a recently reported petrosal from the upper Oligocene Belgrade Formation of North Carolina as Echovenator sp., and permit referral of two additional Belgrade Formation petrosals to Albertocetus meffordorum and Echovenator sp. Future collecting efforts in North Carolina are expected to yield other cetaceans conspecific with those from the contemporaneous Chandler Bridge Formation of South Carolina.

3. The endocast of Albertocetus meffordorum is intermediate in morphology between extant odontocetes and archaeocete whales. Endocast volume indicates that Albertocetus meffordorum is the most highly encephalized odontocete from the early Oligocene (EQ = 2.586), well within the range of extant delphinoids, and chronicling a drastic jump in EQ across the Eocene-Oligocene boundary. Further study of appropriate body size estimation is needed to investigate the proposed Eocene-Oligocene explosion in odontocete encephalization.

4. The sample size of Albertocetus meffordorum permits the first basic examination of ontogenetic trends in stem Odontoceti. Ontogenetic study of Albertocetus meffordorum identifies several sutures of the dorsal braincase and facial region of interest for assessing ontogenetic status in stem Odontoceti (e.g. median parietal suture, frontoparietal suture, frontonasal suture, parieto-occipital suture), to be confirmed with larger samples of undescribed xenorophids (e.g. Echovenator, Xenorophus). Postcranial epiphyseal fusion is achieved earlier in ontogeny than cranial suture closure in A. meffordorum.

5. Vertebral proportions indicate that Albertocetus meffordorum, like basilosaurids, Mysticeti, and sperm whales, is a "pattern 1" species with no anteroposterior specialization of the vertebral column. This indicates that dorsoventral undulation occurred through the entire flexible lumbocaudal series; this appears to characterize stem odontocetes. Rectangular caudal vertebrae indicate the presence of caudal flukes. Surprisingly, no caudal vertebrae are transversely narrower than tall, suggesting the absence of a transversely narrowed peduncle as in all extant Mysticeti and Odontoceti. Such a feature would imply that the narrow peduncle evolved independently. However, skeletons of stem odontocetes and mysticetes with a more complete caudal series are required to further evaluate this hypothesis.

Robert W. Boessenecker,  Erum Ahmed and  Jonathan H. Geisler. 2017. New Records of the Dolphin Albertocetus meffordorum (Odontoceti: Xenorophidae) from the lower Oligocene of South Carolina: Encephalization, Sensory Anatomy, Postcranial Morphology, and Ontogeny of early Odontocetes. PLoS ONE. 12(11); e0186476.  DOI: 10.1371/journal.pone.0186476

New postcranial skeleton of ancient dolphin Albertocetus meffordum found in South Carolina  phy.so/429369468 via @physorg_com

 blogs.cofc.edu/macebrownmuseum/2017/11/10/friday-fossil-feature-4-specimens-are-dolphinately-better-than-1/

 blogs.plos.org/paleocomm/2017/11/08/author-interview-bobby-boessenecker-on-albertocetus

 twitter.com/CoastalPaleo/status/928396997735993345

 twitter.com/tetrameryx/status/929095659667492870
Fossils in @CofCNatHistory collections @CofC