American Museum Novitates

Permanent URI for this collectionhttps://hdl.handle.net/2246/9

The Novitates (Latin for "new acquaintances"), published continuously and numbered consecutively since 1921, are short papers that contain descriptions of new forms and reports in zoology, paleontology, and geology. New numbers are published at irregular intervals.

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Open Access
A new genus for the “Alfaroi Group” of Oryzomys sensu lato (Rodentia, Cricetidae, Sigmodontinae) (American Museum novitates, no. 4030)
(American Museum of Natural History., 2024-12-04) Voss, Robert S.
A new cricetid rodent genus is described for the Alfaroi Group of Oryzomys sensu lato. The new genus, which includes seven Mesoamerican species of small oryzomyines, is demonstrably monophyletic and easily diagnosed morphologically from its sister taxon, Handleyomys.
Open Access
Unravelling parallel conceptions of the Ordovician trilobite Flexicalymene senaria (Conrad, 1841) and description of Flexicalymene trentonensis, n. sp. (American Museum novitates, no. 4029)
(American Museum of Natural History., 2024-11-26) Hopkins, Melanie J.; Martin, Markus J.
Over the past 180 years, there has been occasional observation that museum collections of specimens identified as “Calymene senaria” or “Flexicalymene senaria” comprise more than one species. This was first recognized within a year after the species was named and has been remarked upon as recently as 2002. Perusal of compiled literature in concert with examination of new and historical collections at the American Museum of Natural History, the New York State Museum, Paleontological Research Institution, and Harvard Museum of Comparative Zoology, reveals that this history is due to the perpetuation of parallel conceptions of this species, in part because of the lack of an original type and relatively recent adoption of a neotype (Ross, 1967), as well as the application of the name to specimens from a wide range of localities. We review the taxonomic history of Flexicalymene senaria (Conrad, 1841) and provide a formal description of a second species, which we designate Flexicalymene trentonensis, n. sp. In addition we note that many specimens in museum collections of “senaria” also include specimens of the genus Gravicalymene. We correct taxonomic assignments for over 350 specimen lots housed in the above repositories, and describe how the clarification of this taxonomic history impacts our understanding of important faunal assemblages (Walcott-Rust Quarry, NY) and the reinterpretation of previously documented phyletic patterns.
Open Access
A new archaeostomatopod from the Pennsylvanian Wea Shale Member, Nebraska (American Museum novitates, no. 4028)
(American Museum of Natural History., 2024-11-06) Bicknell, Russell D. C.; Smith, Patrick M. (Patrick Mark); Klompmaker, Adiël A.; Hegna, Thomas.
Mantis shrimp (Stomatopoda) are extant, marine, predatory arthropods, but these malacostracan pancrustaceans are also occasionally preserved in fossil assemblages, particularly in Carboniferous and Cretaceous deposits. Carboniferous species fall into two suborders—Palaeostomatopodea and Archaeostomatopodea—and represent the ancestral forms that gave rise to modern lineages. Herein, we describe hitherto unknown specimens belonging to the archaeostomatopod genus Tyrannophontes from the Pennsylvanian-aged Wea Shale Member, eastern Nebraska. We explore the preservation of these fossils using scanning electron microscopy and energy dispersive X-ray spectroscopy. These approaches reveal additional morphological characteristics, including unique appendicular data, such as the earliest occurrence of biramous gilled appendages in Stomatopoda. We suggest that further examination of black shales will likely uncover novel records of these rare pancrustaceans.
Open Access
An atlas of malformed trilobites from North American repositories. Part 2. The American Museum of Natural History (American Museum novitates, no. 4027)
(American Museum of Natural History., 2024-09-18) Bicknell, Russell D. C.; Smith, Patrick M.; Hopkins, Melanie J.
Trilobites with malformations present important insight into the paleoecology of the wholly extinct arthropod group. This includes records of failed predation, developmental complications, and parasitic interactions. The documentation of malformed trilobites therefore allows for a more thorough understanding of these animals. Such summaries also permit larger-scale, synthetic works that consider patterns and processes associated with malformations to be developed. To expand the current record of malformed Cambrian through to Devonian trilobites, we report 16 novel specimens across 12 genera from deposits spanning Australia, Bolivia, Canada, the United States, and Wales. These specimens illustrate examples of injuries potentially caused by predation, molting, and accidental injury, teratological malformations, and pathological infestation. Possible predators; explanations for developmental, genetic, and recovery issues; as well as infestations are considered. Comparison of size distributions of malformed and nonmal formed Elrathia kingii indicates that primarily the largest specimens preserve malformations. This implies that either smaller specimens fully recovered from malformations or did not survive once the malformations were incurred. Continued documentation of malformed specimens will allow larger datasets to be compiled and further promote the use of malformations in understanding trilobite paleoecology.
Open Access
An atlas of malformed trilobites from North American repositories. Part 1. The Indiana University Paleontological Collection (American Museum novitates, no. 4026)
(American Museum of Natural History., 2024-09-18) Bicknell, Russell D. C.; Smith, Patrick M.; Miller-Camp, Jessica.
Malformed trilobites have been well documented within the arthropod fossil record and serve as valuable evidence for illustrating aspects of trilobite paleoecology associated with development, predation, and pathologies. Ongoing efforts to comprehensively document these malformations have uncovered important, often unique records for the extinct group, shedding light on post-malformation recovery processes and potential predators. A key means of recording new examples of these specimens has been the examination of historically important paleontological collections. To expand this approach, we examined the Deiss collection in the Indiana University Paleontology Collection and present four examples of malformations from Cambrian (Asaphiscus wheeleri, Dorypyge bispinosa, Wanneria walcottana), and Ordovician (Isotelus iowensis) species. These specimens reveal evidence of injuries, failed predation, and developmental complications. We explore the possible explanations for malformations and consider the current state of the art for evaluating trilobite malformations. Finally, the Deiss collection history and its ongoing contributions to Paleozoic fossils are presented.
Open Access
Systematics of Ectrichodiella Fracker and Bruner, 1924 : with description of the first fossil millipede assassin bug species (Insecta, Hemiptera, Reduviidae, Ectrichodiinae) (American Museum novitates, no. 4025)
(American Museum of Natural History., 2024-08-20) Bush, Tatiana.; Berenger, Jean-Michel.; Gil-Santana, Hélcio R.; Forthman, Michael.; Hoey-Chamberlain, R. (Rochelle); Weirauch, Christiane.
With more than 886 species in ~137 genera, Ectrichodiinae (Hemiptera: Reduviidae) are the largest animal clade of millipede predators. Recent phylogenetic studies have created a framework for our understanding of ectrichodiine evolutionary history, but no fossil species have been described. Ectrichodiella Fracker and Bruner, 1924, belongs to the earliest diverging lineage of Ectrichodiinae, and a better understanding of the morphology and biodiversity of this genus may provide insights into the early evolution of the subfamily. The genus is composed of two described species, Ectrichodiella minima (Valdés, 1910) and Ectrichodiella rafaeli (Gil-Santana and Coletto-Silva, 2005) from Cuba and Brazil, respectively. Here, four new species of Ectrichodiella are described, with three representing extant taxa known only from French Guiana (E. caballina, n. sp., E. nouraguensis, n. sp., and E. obscura, n. sp.), while the fourth is based on a Miocene Dominican amber fossil (Ectrichodiella electrina, n. sp.). Diagnoses, descriptions, habitus and detailed morphological images, an identification key, and a distribution map are provided. A cladistic analysis based on 45 morphological characters that includes the fossil species corroborates the monophyly of Ectrichodiella, but the relationship of the fossil species to the five extant species remains ambiguous. Nevertheless, this phylogenetic placement makes Ectrichodiella electrina, a valuable fossil calibration for future divergence dating analyses, despite its relatively young age.
Open Access
A revised diagnosis of the blood-feeding candiru genus Paravandellia (Siluriformes, Trichomycteridae, Vandelliinae) : with descriptions of three new species (American Museum novitates, no. 4024)
(American Museum of Natural History., 2024-06-28) Henschel, Elisabeth.; Baskin, Jonathan N.; Collins, Rupert A.; Lujan, Nathan K.
The taxonomy of the blood-feeding candiru catfish genus Paravandellia is poorly resolved, incomplete, and hindered by a complex nomenclatural history, with many species being arbitrarily synonymized, considerable morphological and geographic variation being unevaluated, and morphological boundaries between the genus and its sister, Paracanthopoma, differing among authors. Herein, we describe three new species of Paravandellia based on photomicroscopy, cleared and stained specimens, and µCT imagery. We also reevaluate diagnostic character states for Paravandellia and Paracanthopoma, propose a new character to diagnose Paravandellia, and present our discovery of a possible type specimen of Parabranchioica teaguei and additional non-type specimens of Branchioica bertoni, junior synonyms of Parav. oxyptera. Based on these observations, we confirm Parav. alleynei and a recent newly described species of Paracanthopoma as members of a rediagnosed, putatively monophyletic Paravandellia, increasing its richness from two to seven species. We also discuss interrelationships of Paravandellia species based on the characters described.
Open Access
Cranial anatomy and petrosal morphology of a juvenile individual of Neobrachytherium (Proterotheriidae, Litopterna, Mammalia) (American Museum novitates, no. 4023)
(American Museum of Natural History., 2024-06-28) Armella, Matías A.; García López, Daniel A. (Daniel Alfredo); Croft, Darin A.
South America underwent a span of isolation in the Cenozoic, during which an endemic fauna developed, including a diverse group of native ungulates. Among them, Proterotheriidae (Litopterna, Pan-Perissodactyla) were small to medium-sized hoofed herbivores mainly documented from the Oligocene to the Pleistocene. The study of proterotheriid mammals, specifically their cranial morphology, has been challenging due to the limited availability of materials, leading to a heavy reliance on dental evidence in their descriptions. This issue is particularly evident for late Neogene records, where comprehensive cranial studies have been lacking. Herein, we study a juvenile proterotheriid individual referred to Neobrachytherium intermedium recovered from Early Pliocene outcrops of northwestern Argentina. Our research focuses on cranial morphology, particularly on the dorsal and orbitotemporal regions, mesocranium, and basicranial structures. By employing noninvasive techniques, we describe the petrosal anatomy and compare it in a broader phylogenetic context. We also provide insights into ontogenetic stages within the genus. We find singular arrangements and structures for the genus (e.g., tuberosities in the postglenoid process) as well as traits shared with other mammals that are distinct from those found in other SANUs and pan-perissodactyls, such as Notoungulata (e.g., ringlike ectotympanic, gracile tympanohyal, poorly developed epitympanic wing and medial flange, large hiatus Fallopii). Traits such as the position and shape of the m. tensor tympani fossa and the development of the jugular notch may be synapomorphies of Litopterna, but this cannot be determined without resolving the phylogenetic position of Indalecia grandensis, which has been suggested to be a basal Litopterna. Considering ontogenetic observations, features like the frontal sulcus, the supraorbital foramen, and the palate configuration exhibit age-related changes. The occlusal patterns of teeth undergo substantial changes with wear, affecting loph morphology. Variations in deciduous premolars are observed within the same individual. These findings emphasize the importance of considering ontogenetic and individual variations when analyzing cranial and dental remains for taxonomic and phylogenetic purposes. The study provides valuable information for understanding late Neogene proterotheriids and the broader context of cranial evolution within Litopterna, highlighting the necessity for more comprehensive research.
Open Access
The cuckoo bee genus Pasites in Central Vietnam (Hymenoptera, Apidae) (American Museum novitates, no. 4022)
(American Museum of Natural History., 2024-06-28) Tran, Ngat Thi.; Engel, Michael S.; Nguyen, Manh Thanh.; Nguyen, Cuong Quang.; Nguyen, Lien Thi Phuong.
The bee genus Pasites Jurine (Nomadinae: Ammobatini) is recorded from Vietnam for the first time. A new species, Pasites vuquang Tran, Engel, and Nguyen, n. sp., is described and illustrated based on two females and one male collected from Vu Quang National Park, central Vietnam. Its potential host is Pseudapis (Pseudapis) siamensis Cockerell (Halictidae: Nomiinae). An identification key is provided to the species of Asian Pasites.
Open Access
A species complex in the iconic frog-eating bat Trachops cirrhosus (Chiroptera, Phyllostomidae) with high variation in the heart of the Neotropics (American Museum novitates, no. 4021)
(American Museum of Natural History., 2024-06-28) Fonseca, Bruna da Silva.; Soto-Centeno, J. Angel.; Simmons, Nancy B.; Ditchfield, Albert David.
Delimiting species and quantifying their underlying variation is imperative for documenting diversity in highly speciose regions like the Neotropics. To aid with proper delimitation and avoid the perils of inflating or underestimating taxonomic units, approaches combining environmental, genetic, and phenotypic data are essential to provide a holistic perspective based on integrative taxonomy. A multiple-evidence approach is particularly useful when dealing with cryptic or iconic (i.e., easy to identify) species that might contain hidden diversity. We studied the phylogeography of one such species, the frog-eating bat (Trachops), and examined species limits throughout its broad range in the Neotropics. Following previous studies, we tested the hypotheses that Trachops is a monotypic genus with high intraspecific genetic and phenotypic diversity. Multilocus phylogenetics and species-delimitation analyses showed that Trachops consists of at least three species that diverged between seven to three million years ago. Taxonomic limits of three species-level groups recognized in our study (T. cirrhosus, T. coffini, and T. ehrhardti) are confirmed by a cranial morphometric analysis of over 800 individuals and craniodental features. Ecological niche models revealed that each of these groups occupies a distinct niche, and heterogeneous environmental gradients and biogeographic barriers could be responsible for maintaining the limits of these taxa. This study sheds new light into the taxonomy of Trachops that can be important for conservation management in Neotropical areas with a fast rate of deforestation.
Open Access
The unnatural grouping of Deuterodiscoelius Dalla Torre, 1904, and Pachycoelius Giordani Soika, 1969 (Hymenoptera, Vespidae), and a remarkable new species (American Museum novitates, no. 4020)
(American Museum of Natural History., 2024-06-21) Botion Lopes, Rogério.; Carpenter, James M. (James Michael), 1956-; Noll, Fernando B. (Fernando Barbosa)
Deuterodiscoelius Dalla Torre and Pachycoelius Giordani Soika are two small genera of Australian vespid wasps. While the first came from the splitting of Discoelius, the latter was created to accommodate species with a few distinct traits, some of which were not observable due to the absence of male specimens of two out of the three species designated to the genus. This already blurry delimitation of the genera was heightened when specimens of an unknown species presented a combination of characters from both genera. Hence, to properly assign this species to a genus, a phylogenetic study based on morphology was carried out before the species description. The analysis recovered both genera as unnatural, resulting in the synonymy of Pachycoelius under Deuterodiscoelius, and the new species, namely, Deuterodiscoelius delator Lopes and Carpenter, new species, was subsequently described.
Open Access
Richness, complementarity, and community structure of Amazonian mammal faunas : results from multiyear inventories in French Guiana and Peru (American Museum novitates, no. 4019)
(American Museum of Natural History., 2024-06-21) Voss, Robert S.
Mammal faunas from northern French Guiana (in northeastern Amazonia) and the Yavarí-Ucayali interfluve (in southwestern Amazonia) are the first Amazonian mammal faunas to be comprehensively described in terms of taxonomic composition and community structure. Bats are the most speciose group in each fauna, followed in order of decreasing species richness by rodents, didelphimorphians, carnivorans, xenarthrans or primates, and ungulates. A total of 180 species are known from northern French Guiana and 199 species from the Yavarí-Ucayali interfluve, but an additional 25 species are possibly missing (“pseudoabsent”) from the Yavarí-Ucayali interfluvial inventory; therefore, the increment by which species richness in northeast- ern Peru exceeds that of northern French Guiana is on the order of 10–25%. Complementarity (dissimilarity) between these faunas is high (79%–89%) for opossums, primates, and rodents, but complementarity is substantially lower for other groups (especially bats, carnivorans, and ungulates), suggesting taxonomic differences in geographic filtering. Most species in both faunas are nocturnal, as might be expected from the abundance of bats, but even among nonflying mammals nocturnal species outnumber diurnal species by about 2:1. Approximately equal numbers of nonflying species in both faunas are arboreal or terrestrial, whereas much smaller numbers are scansorial or semiaquatic; with one possible exception, none is fossorial. Despite such behavioral similarities, these faunas differ in trophic composition and guild membership: substantially more primary consumers are present in the Yavarí-Ucayali interfluve than in northern French Guiana, whereas numbers of secondary consumers and omnivores are similar. Higher primary productivity in western Amazonia, a geomorphologically dynamic landscape with fertile soils and phenologically diverse habitats, could explain faunal differences in both species richness and trophic structure.
Open Access
A morphological assessment of Osgood’s 1918 application of Otognosis longimembris Coues, 1875 (Rodentia, Heteromyidae), with the proposal of a neotype (American Museum novitates, no. 4018)
(American Museum of Natural History., 2024-06-21)
We review the current usage of the species-group names Perognathus inornatus Merriam, 1889, for the San Joaquin Pocket Mouse and P. longimembris (Coues, 1875) for the Little Pocket Mouse. Wilfred Osgood, in two papers published 18 years apart at the beginning of the 20th Century, provided conflicting applications of these names, with his second assignments in common use since 1918. Contrary to this prevailing usage, we show that the skull of the holotype of longimembris is best allocated to the San Joaquin form, as Osgood had originally concluded in 1900. To maintain stability and universality of current usage (International Code of Zoological Nomenclature: Article 75.6), we propose a neotype from the Antelope Valley of California as a replacement for Coues’s holotype of longimembris.
Open Access
Caste differences and morphological skew in the swarm-founding wasp Agelaia timida Cooper, 2000 (Hymenoptera, Vespidae, Epiponini) (American Museum novitates, no. 4017)
(American Museum of Natural History., 2024-06-21) Noll, Fernando B. (Fernando Barbosa); da Silva, Marjorie.; Somavilla, Alexandre.; Carpenter, James M. (James Michael), 1956-
Here, we tested the application of morphological skew in Agelaia timida by reporting caste dimorphism and comparing it with other epiponine species. A description of a nest of A. timidais also provided. Females were measured to investigate morphological differences between castes and dissected to assess ovarian development. Three types of ovaries were found: filamentous (workers), developed with some mature oocytes (intermediates), and developed and inseminated (queens). Queens are bigger than workers, but discriminant analysis showed castes are not morphologically distinct. Mahalanobis distance showed a statistical separation between inseminated and non-inseminated females, and the only distinct group was workers. The results differ from other species of Agelaia, which present clear-cut caste differences. Thus, A. timida fits into morphological skew theory since it forms small colonies with low caste differentiation and nonsterility of workers. These features, plus the presence of a true envelope, may be plesiomorphic, as observed in the ground plan of Epiponini.
Open Access
Phylogenetic relationships of two poorly known Honduran treefrogs (Hylidae, Hylinae, Hylini) : review, revisions, and three new species (American Museum novitates, no. 4016)
(American Museum of Natural History., 2024-05-31) Chaves-Acuña, Wagner.; Boza-Oviedo, Eduardo.; Zúniga Betanco, Javier Antonio.; Chaves Cordero, Gerardo Antonio.; Bolaños, Federico (Bolaños Vives); McCranie, James R.; Vásquez-Almazán, Carlos R.; Faivovich, Julián.
Isthmohyla insolita and Exerodonta catracha are Honduran hylids of uncertain phylogenetic relationships. In this paper we present a phylogenetic analysis of mitochondrial and nuclear genes to study their relationships. Our results show that these species are, respectively, the sister taxon of and nested among the few available species of Plectrohyla, possibly the least studied genus of Hylini in terms of phylogenetic relationships. To solve the polyphyly of Exerodonta and Isthmohyla, both species are provisionally transferred to Plectrohyla, pending a broader phylogenetic study including all species in the genus. Consequently, Isthmohyla is restricted to a group of hylids endemic to the Isthmian highlands of Costa Rica and Panama in lower Central America. The inclusion of I. insolita in Plectrohyla implies another instance of independent evolution of terrestrial egg clutches in Hylini.
Open Access
The Drosophila (Sophophora) obscura species group in the Americas (Diptera, Drosophilidae) : review, revisions, and three new species (American Museum novitates, no. 4015)
(American Museum of Natural History., 2024-05-16) Grimaldi, David A.
Flies in the Drosophila (Sophophora) obscura species group are among the most common native drosophilids in northern temperate and boreal forests; southward, into cool, montane tropical forests they are rare and localized, but diverse. Of the world’s 48 species, 18 occur in the New World, including three new neotropical species described here. Here, all New World species are diagnosed, many with images and the use of some new morphological features such as female terminalia (oviscapt and spermathecal structure). A basic phylogenetic scheme of relationships based on 19 morphological characters corresponds well with molecular trees. Type series have been rediscovered of D. algonquin, athabasca, azteca, narragansett, and seminole (all described by Sturtevant and Dobzhansky in 1936), from which a lectotype is designated for each of the first four species and the holotype is recognized for seminole. Drosophila narragansett from the eastern United States, which has been found only once in 60 years, is redescribed in detail from historical material; D. seminole is found to be a synonym of narragansett. The three new species are Drosophila chibcha, n. sp. (from Costa Rica to Venezuela and Peru), D. olmeca, n. sp. (from southern Mexico), both of these in the affinis subgroup; and D. zapoteca, n. sp. (from Guatemala), in the pseudoobscura subgroup. Significant new distributional and host records are reported for various species.
Open Access
Revision of the genus Actinostella (Cnidaria, Actiniaria, Actinioidea) from tropical and subtropical western Atlantic and eastern Pacific : redescriptions and synonymies (American Museum novitates, no. 4014)
(American Museum of Natural History., 2024-05-08) Barragán, Yamaly.; Rodríguez, Estefanía.; Chiodo, Tommaso.; Gusmão, Luciana Câmara, 1981-; Sánchez Ortiz, Carlos A.; Lauretta, Daniel.
Sea anemone species of the genus Actinostella live in tropical and subtropical shallow waters. They are characterized by having a marginal ruff harboring zooxanthellae that expands during the day and retracts at night, allowing the anemone to catch prey with the tentacles. Currently, 10 or 11 species are considered valid depending on the author; however, most species within the genus were described in the 1800s or in early 1900s and, thus, most descriptions are incomplete by modern standards. In addition, several species of Actinostella have reported wide geographical distributions. We evaluate the morphology of newly collected and type material to assess potential synonymies and geographical distributions; we perform phylogenetic analysis using five standard molecular rDNA markers for sea anemones to corroborate our morphological results and to investigate the phylogenetic relationships of Actinostella, other actinioideans, and those Actinostella species present in the eastern Pacific and western Atlantic tropical region. Based on morphological and cnida differences, we find six species of Actinostella valid. We redescribe A. bradleyi, A. californica, A. digitata, and A. flosculifera and synonymize A. californica pro parte (Pacific specimens with four cycles of mesenteries and p-mastigophores A in the marginal ruff) with A. bradleyi (found in the Panamanian and Mexican Pacific and the Gulf of California). We also find that A. ornata does not belong within Actinostella. We discuss the membership of Actinostella, including species of the genus Phyllactis, and synonymize Phyllactis with Actinostella. We propose that the combination of the presence of p-mastigophores A in the marginal ruff and the arrangement and fertility of mesenteries are diagnostic characteristics to differentiate species of Actinostella from the American coasts. Finally, our phylogenetic analyses based on rDNA markers differentiated between the western Atlantic and eastern Pacific species but lacked support and resolution to elucidate relationships within species in the eastern Pacific.
Open Access
A composite section of fossiliferous Late Cretaceous--Early Paleogene localities in Senegal and preliminary description of a new late Maastrichtian vertebrate fossil assemblage (American Museum novitates, no. 4013)
(American Museum of Natural History., 2024-05-08) Sarr, Raphaël.; Hill, Robert V.; Jenkins, Xavier A.; Tapanila, Leif.; O'Leary, Maureen A.
We describe new macro- and microfossils recovered on a field expedition to the North Quarry of Poponguine, a locality in western Senegal that spans the Late Cretaceous through the Early Paleogene, albeit with a likely unconformity at the base of the Danian. Newly discovered macrovertebrates from the Maastrichtian Cap de Naze Formation include pycnodonts, dyrosaurids, and chelonians, the latter two the oldest and first Cretaceous representatives of these clades from Senegal. Screenwashing of this deposit revealed that the matrix also consists of abundant microscopic biological clasts comprising osteichthyan vertebrae, spines, and cranial fragments, shark dermal denticles, invertebrates, and numerous ovoid coprolites among other fragments. These microfossils document a much less conspicuous portion of the paleobiodiversity. We describe the stratigraphy of this new locality and incorporate it into a new correlated section that ties together three other Late Cretaceous--Early Paleogene fossiliferous localities of the Senegalese-Mauritanian Basin. The presence of fossiliferous Danian rocks, which are notably rare in West Africa, is elucidated in our section, which synthesizes prior geological and paleontological work around Poponguine and in the nearby coastal region of Ndayane. Primarily dated using the biostratigraphy of ostracods and foraminiferans, the correlated rock units include the Paki and the Cap de Naze Formations of the Late Cretaceous Diass Group and the Ndayane and the Poponguine Formations of the Paleocene Cap-Vert Group, deposits that capture ancient near shore marine environments. The localities described, although separated by only a few kilometers, exhibit dramatic differences in thickness across faulted blocks of the Diass Horst. Dyrosaurids, which are common fossils in nearshore marine outcrops of West Africa, have been hypothesized to be of African origin and to have dispersed to South America in the Late Cretaceous. This dyrosaurid specimen, although fragmentary, documents a western extreme in the geographic range of African dyrosaurids where the clade would have been well situated for broader trans-Atlantic dispersal.
Open Access
A new extinct species of Malagodon (Cyprinodontiformes: Pantanodontidae) from southeastern coastal Madagascar : with a discussion of its phylogenetic relationships and a redescription of the genus (American Museum novitates, no. 4012)
(American Museum of Natural History., 2024-04-24) Carr, Emily M.; Martin, Rene P.; Sparks, John S.
A new species belonging to the recently described genus Malagodon Meinema and Huber, 2023, is herein described from specimens collected in a single, small, isolated Pandanas swamp in southeastern coastal Madagascar, located within the Réserve Spéciale de Manombo, south of the town of Farafangana, its only known locality. The new species was last collected in the late 1990s, and despite repeated attempts over the past three decades, no additional specimens have been collected at the type locality or from any other suitable habitats within the region, and the species is presumed to be extinct. The new species is distinguished from its only congener, Malagodon madagascariensis, formerly known from forested swamps in northeastern coastal Madagascar, and also now considered to be extinct, by the following apomorphic features: a lower anal-fin ray count (15–17 vs. 18–19), a longer caudal peduncle (26.8%–39.8% vs. 21.9%–26.7% SL), and the presence of a platelike (vs. thin and spinelike) neural spine on the fifth vertebral centrum in both sexes. Additionally, the new species exhibits neural spines on both the sixth and seventh vertebral centra that are also somewhat expanded and platelike dorsally compared with those in M. madagascariensis, which are narrow and spinelike. We also provide a rediagnosis of Malagodon based on the examination of additional material unavailable in the original description, which was based on only three specimens (two males of M. madagascariensis and one female of the new species).
Open Access
Phylogeny of the Troglomorphic scorpion genus Troglotayosicus (Scorpiones: Troglotayosicidae) : with description of a new species from Colombia (American Museum novitates, no. 4011)
(American Museum of Natural History., 2024-04-12) Moreno-González, Jairo A.; Luna-Sarmiento, David A.; Prendini, Lorenzo.
The troglomorphic scorpion genus Troglotayosicus Lourenço, 1981, occurs in hypogean and epigean habitats in the Andean and Amazonian rainforests of Colombia and Ecuador. The phylogenetic relationships among the species of Troglotayosicus are currently unknown. In the present contribution, a new species, Troglotayosicus akaido, sp. nov., is described from specimens collected in the leaf litter of a primary rainforest in the Colombian Amazon, near the border with Peru, raising the number of species in the genus to seven. The new species represents the easternmost record of the genus and further extends its distribution into the Amazon. Its phylogenetic position was tested in an analysis of all species of the genus and two outgroup taxa, scored for 131 morphological characters (16 new and 115 legacy; 104 binary and 27 multistate) analyzed with maximum likelihood under the MK model. Troglotayosicus was recovered as monophyletic and composed of two main clades. The morphological survey revealed that the ventral macrosetae of the leg telotarsi of the type species, Troglotayosicus vachoni Lourenço, 1981, are simple, subspiniform macrosetae, irregularly distributed, but not arranged into clusters nor forming elongated clusters of setae/spinules, as previously suggested. A distribution map and key to the identification of the species of Troglotayosicus are provided. Further research, incorporating molecular data, is needed to understand the evolution and biogeographical history of this enigmatic scorpion genus.