1
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Imirzian N, Püffel F, Roces F, Labonte D. Large deformation diffeomorphic mapping of 3D shape variation reveals two distinct mandible and head capsule morphs in Atta vollenweideri leaf-cutter worker ants. Ecol Evol 2024; 14:e11236. [PMID: 38633523 PMCID: PMC11021802 DOI: 10.1002/ece3.11236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 02/21/2024] [Accepted: 03/15/2024] [Indexed: 04/19/2024] Open
Abstract
Ants are crucial ecosystem engineers, and their ecological success is facilitated by a division of labour among sterile "workers". In some ant lineages, workers have undergone further morphological differentiation, resulting in differences in body size, shape, or both. Distinguishing between changes in size and shape is not trivial. Traditional approaches based on allometry reduce complex 3D shapes into simple linear, areal, or volume metrics; modern approaches using geometric morphometrics typically rely on landmarks, introducing observer bias and a trade-off between effort and accuracy. Here, we use a landmark-free method based on large deformation diffeomorphic metric mapping (LDDMM) to assess the co-variation of size and 3D shape in the mandibles and head capsules of Atta vollenweideri leaf-cutter ants, a species exhibiting extreme worker size-variation. Body mass varied by more than two orders of magnitude, but a shape atlas created via LDDMM on μ-CT-derived 3D mesh files revealed only two distinct head capsule and mandibles shapes-one for the minims (body mass < 1 mg) and one for all other workers. We discuss the functional significance of the identified 3D shape variation, and its implications for the evolution of extreme polymorphism in Atta.
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Affiliation(s)
| | | | - Flavio Roces
- Department of Behavioural Physiology and SociobiologyBiocenter, University of WürzburgWürzburgGermany
| | - David Labonte
- Department of BioengineeringImperial College LondonLondonUK
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2
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Griebenow Z. Systematic revision of the ant subfamily Leptanillinae (Hymenoptera, Formicidae). Zookeys 2024; 1189:83-184. [PMID: 38314112 PMCID: PMC10838183 DOI: 10.3897/zookeys.1189.107506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/06/2023] [Indexed: 02/06/2024] Open
Abstract
The genus-level taxonomy of the ant subfamily Leptanillinae (Hymenoptera: Formicidae) is here revised, with the aim of delimiting genus-level taxa that are reciprocally monophyletic and readily diagnosable based upon all adult forms. This new classification reflects molecular phylogenetics and is informed by joint consideration of both male and worker morphology. Three valid genera are recognized in the Leptanillinae: Opamyrma, Leptanilla (= Scyphodonsyn. nov., Phaulomyrma, Leptomesites, Noonillasyn. nov., Yavnellasyn. nov.), and Protanilla (= Anomalomyrmasyn. nov., Furcotanilla). Leptanilla and Protanilla are further divided into informal, monophyletic species groups. Synoptic diagnoses are provided for all genera and informal supraspecific groupings. In addition, worker-based keys to all described species within the Leptanillinae for which the worker caste is known are provided; and male-based keys to all species for which males are known, plus undescribed male morphospecies for which molecular data are published. The following species are described as new: Protanillawallaceisp. nov., Leptanillaacherontiasp. nov., Leptanillabelantansp. nov., Leptanillabethyloidessp. nov., and Leptanillanajaphallasp. nov.
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Affiliation(s)
- Zachary Griebenow
- Department of Entomology & Nematology, University of California, Davis, CA USAUniversity of CaliforniaDavisUnited States of America
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO USAColorado State UniversityFort CollinsUnited States of America
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3
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Richter A, Economo EP. The feeding apparatus of ants: an overview of structure and function. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220556. [PMID: 37839452 PMCID: PMC10577024 DOI: 10.1098/rstb.2022.0556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 06/25/2023] [Indexed: 10/17/2023] Open
Abstract
Ants are a dominant family of eusocial terrestrial insects with a diversity of ecologies, lifestyles and morphologies. Ant diet preferences range from strict carnivory through omnivory to almost complete herbivory in species feeding on seeds or exudates of plant-sucking insects. While several studies have investigated ant feeding performance on different substrates, comparatively little is known about the functional morphology of the structures involved in food uptake or their diversification across the ants. To take stock of our current knowledge, we give an overview of how adult ants ingest food, followed by a morphological description of the mouthparts, preoral space and cephalic sucking pump. The mandibles are the most prominent mouthparts and have received considerable attention in the literature, so we focus on the maxillae and labium here. We present current hypotheses for the movement patterns of these parts and discuss morphological differences among ants that may be related to their ecological diversity. Finally, we give short comparisons of the ant condition with some other insects and vertebrates, as well as an outlook summarizing gaps in our knowledge. This sets the stage for future studies elucidating the connections between ant feeding mechanisms and mouthpart evolution. This article is part of the theme issue 'Food processing and nutritional assimilation in animals'.
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Affiliation(s)
- Adrian Richter
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1, Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Evan P Economo
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1, Tancha, Onna-son, Okinawa 904-0495, Japan
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4
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Klunk CL, Argenta MA, Rosumek FB, Schmelzle S, van de Kamp T, Hammel JU, Pie MR, Heethoff M. Simulated biomechanical performance of morphologically disparate ant mandibles under bite loading. Sci Rep 2023; 13:16833. [PMID: 37803099 PMCID: PMC10558566 DOI: 10.1038/s41598-023-43944-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 09/30/2023] [Indexed: 10/08/2023] Open
Abstract
Insects evolved various modifications to their mouthparts, allowing for a broad exploration of feeding modes. In ants, workers perform non-reproductive tasks like excavation, food processing, and juvenile care, relying heavily on their mandibles. Given the importance of biting for ant workers and the significant mandible morphological diversity across species, it is essential to understand how mandible shape influences its mechanical responses to bite loading. We employed Finite Element Analysis to simulate biting scenarios on mandible volumetric models from 25 ant species classified in different feeding habits. We hypothesize that mandibles of predatory ants, especially trap-jaw ants, would perform better than mandibles of omnivorous species due to their necessity to subdue living prey. We defined simulations to allow only variation in mandible morphology between specimens. Our results demonstrated interspecific differences in mandible mechanical responses to biting loading. However, we found no evident differences in biting performance between the predatory and the remaining ants, and trap-jaw mandibles did not show lower stress levels than other mandibles under bite loading. These results suggest that ant feeding habit is not a robust predictor of mandible biting performance, a possible consequence of mandibles being employed as versatile tools to perform several tasks.
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Affiliation(s)
- C L Klunk
- Graduate Program in Ecology and Conservation, Universidade Federal do Paraná, Centro Politécnico, Av. Cel. Francisco H. dos Santos, 100 - Jardim das Américas, Curitiba, PR, 81531-980, Brazil.
- Animal Evolutionary Ecology, Technische Universität Darmstadt, Schnittspahnstr. 3, 64287, Darmstadt, Germany.
| | - M A Argenta
- Department of Civil Construction, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - F B Rosumek
- Department of Ecology and Zoology, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - S Schmelzle
- Animal Evolutionary Ecology, Technische Universität Darmstadt, Schnittspahnstr. 3, 64287, Darmstadt, Germany
| | - T van de Kamp
- Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
- Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - J U Hammel
- Institute of Materials Physics, Helmholtz-Zentrum Hereon, Geesthacht, Germany
| | - M R Pie
- Biology Department, Edge Hill University, Ormskirk, Lancashire, UK
| | - M Heethoff
- Animal Evolutionary Ecology, Technische Universität Darmstadt, Schnittspahnstr. 3, 64287, Darmstadt, Germany.
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5
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Klunk CL, Argenta MA, Casadei‐Ferreira A, Pie MR. Mechanical demands of bite in plane head shapes of ant (Hymenoptera: Formicidae) workers. Ecol Evol 2023; 13:e10162. [PMID: 37293120 PMCID: PMC10244895 DOI: 10.1002/ece3.10162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/16/2023] [Accepted: 05/24/2023] [Indexed: 06/10/2023] Open
Abstract
Food processing can exert significant evolutionary pressures on the morphological evolution of animal appendages. The ant genus Pheidole displays a remarkable degree of morphological differentiation and task specialization among its workers. Notably, there is considerable variation in head shape within worker subcastes of Pheidole, which could affect the stress patterns generated by bite-related muscle contraction. In this study, we use finite element analysis (FEA) to investigate the effect of the variation in head plane shape in stress patterns, while exploring the morphospace of Pheidole worker head shapes. We hypothesize that the plane head shapes of majors are optimized for dealing with stronger bites. Furthermore, we expect that plane head shapes at the edges of each morphospace would exhibit mechanical limitations that prevent further expansion of the occupied morphospace. We vectorized five head shapes for each Pheidole worker type located at the center and edges of the corresponding morphospaces. We conducted linear static FEA to analyze the stresses generated by mandibular closing muscle contraction. Our findings indicate that plane head shapes of majors exhibit signs of optimization to deal with stronger bites. Stresses are distinctly directed along the lateral margins of the head, following the direction of muscle contraction, whereas the stresses on the plane head shapes of minors tend to concentrate around the mandibular articulations. However, the comparatively higher stress levels observed on majors' plane head shapes suggest a demand for cuticular reinforcement, like increased cuticle thickness or sculpturing pattern. Our results align with the expectations regarding the main colony tasks performed by each worker subcaste, and we find evidence of biomechanical limitations on extreme plane head shapes for majors and minors.
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Affiliation(s)
- Cristian L. Klunk
- Graduate Program in Ecology and ConservationUniversidade Federal do ParanáCuritibaBrazil
| | - Marco A. Argenta
- Department of Civil ConstructionUniversidade Federal do ParanáCuritibaBrazil
| | - Alexandre Casadei‐Ferreira
- Biodiversity and Biocomplexity UnitOkinawa Institute of Science and Technology Graduate UniversityOnnaJapan
| | - Marcio R. Pie
- Department of BiologyEdge Hill UniversityOrmskirkUK
- Department of ZoologyUniversidade Federal do ParanáCuritibaBrazil
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6
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Smith CR. Sexual dimorphism as a facilitator of worker caste evolution in ants. Ecol Evol 2023; 13:e9825. [PMID: 36818531 PMCID: PMC9929627 DOI: 10.1002/ece3.9825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/20/2023] [Accepted: 01/27/2023] [Indexed: 02/17/2023] Open
Abstract
Ant societies are primarily composed of females, whereby labor is divided into reproductive, or queen, and non-reproductive, or worker, castes. Workers and reproductive queens can differ greatly in behavior, longevity, physiology, and morphology, but queen-worker differences are usually modest relative to the differences in males. Males are short-lived, typically do not provide the colony with labor, often look like a different species, and only occur seasonally. It is these differences that have historically led to their neglect in social insect research, but also why they may facilitate novel phenotypic variation - by increasing the phenotypic variability that is available for selection. In this study, worker variation in multivariate size-shape space paralleled male-queen variation. As worker variation increased within species, so did sexual variation. Across species in two independent genera, using head width as a proxy for body size, sexual size dimorphism correlated with worker polymorphism regardless of whether the ancestral condition was large or small worker/sexual dimorphism. Mounting molecular data support the hypothesis that queen-worker caste determination has co-opted many genes/pathways from sex determination. The molecular evidence, coupled with the observations from this study, leads to the hypothesis that sexual selection and selection on colony-level traits are non-independent, and that sexual dimorphism may even have facilitated the evolution of the distinct worker caste.
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7
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Boudinot BE, Richter AK, Hammel JU, Szwedo J, Bojarski B, Perrichot V. Genomic-Phenomic Reciprocal Illumination: Desyopone hereon gen. et sp. nov., an Exceptional Aneuretine-like Fossil Ant from Ethiopian Amber (Hymenoptera: Formicidae: Ponerinae). INSECTS 2022; 13:796. [PMID: 36135497 PMCID: PMC9502205 DOI: 10.3390/insects13090796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/01/2022] [Accepted: 08/03/2022] [Indexed: 06/16/2023]
Abstract
Fossils are critical for understanding the evolutionary diversification, turnover, and morphological disparification of extant lineages. While fossils cannot be sequenced, phenome-scale data may be generated using micro-computed tomography (µ-CT), thus revealing hidden structures and internal anatomy, when preserved. Here, we adduce the male caste of a new fossil ant species from Miocene Ethiopian amber that resembles members of the Aneuretinae, matching the operational definition of the subfamily. Through the use of synchrotron radiation for µ-CT, we critically test the aneuretine-identity hypothesis. Our results indicate that the new fossils do not belong to the Aneuretinae, but rather the Ponerini (Ponerinae). Informed by recent phylogenomic studies, we were able to place the fossils close to the extant genus Cryptopone based on logical character analysis, with the two uniquely sharing absence of the subpetiolar process among all ponerine genera. Consequently, we: (1) revise the male-based key to the global ant subfamilies; (2) revise the definitions of Aneuretinae, Ponerinae, Platythyreini, and Ponerini; (3) discuss the evolution of ant mandibles; and (4) describe the fossils as †Desyopone hereon gen. et sp. nov. Our study highlights the value of males for ant systematics and the tremendous potential of phenomic imaging technologies for the study of ant evolution.
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Affiliation(s)
- Brendon E. Boudinot
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Vor dem Neutor 1, 07743 Jena, Germany
| | - Adrian K. Richter
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Vor dem Neutor 1, 07743 Jena, Germany
| | - Jörg U. Hammel
- Institute of Materials Physics, Helmholtz-Zentrum Hereon, Max-Planck-Straße 1, 21502 Geesthacht, Germany
| | - Jacek Szwedo
- Laboratory of Evolutionary Entomology and Museum of Amber Inclusions, Faculty of Biology, University of Gdańsk, 59 Wita Stwosza Street, 80-309 Gdańsk, Poland
| | - Błażej Bojarski
- Laboratory of Evolutionary Entomology and Museum of Amber Inclusions, Faculty of Biology, University of Gdańsk, 59 Wita Stwosza Street, 80-309 Gdańsk, Poland
| | - Vincent Perrichot
- CNRS, Géosciences Rennes, University Rennes, UMR 6118, 35000 Rennes, France
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8
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Perrichot V, Boudinot BE, Engel MS, Xu C, Bojarski B, Szwedo J. Ants (Hymenoptera: Formicidae) from Miocene Ethiopian amber: filling gaps in the geological record of African terrestrial biota. Zool J Linn Soc 2022. [DOI: 10.1093/zoolinnean/zlac053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
The Early Miocene (16–23 Mya) amber of Ethiopia constitutes a new source of fossil ants for Africa, where they are otherwise poorly documented. Here we report a diversified assemblage of six subfamilies and at least 19 genera that are still predominantly alive in the Afrotropics today. In this first account, a particular reference is made to the subfamily Dolichoderinae, with the description of two new species: Technomyrmex svojtkai Perrichot & Engel sp. nov. and Ravavy goldmani Boudinot & Perrichot sp. nov. The first is illustrated and described based on synchrotron-radiation microcomputed tomography, and the second represents the first fossil record for the tribe Bothriomyrmecini and Ravavy, a Malagasy and Afrotropical genus that was hitherto monotypic. The ant composition in Ethiopian amber is congruent with the global pattern emerging across ants and showing a Neogene diversification almost exclusively within extant genera.
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Affiliation(s)
- Vincent Perrichot
- Géosciences Rennes - UMR 6118 , Université de Rennes, CNRS Rennes , France
| | - Brendon E Boudinot
- Institut für Zoologie und Evolutionsforschung , Friedrich-Schiller-Universität Jena, Erberstraße, Jena , Germany
- University of California, Davis , Davis, California , USA
| | - Michael S Engel
- Division of Entomology, Natural History Museum, and Department of Ecology & Evolutionary Biology, University of Kansas , Lawrence, Kansas , USA
- Division of Invertebrate Zoology, American Museum of Natural History , New York, New York , USA
| | - Chunpeng Xu
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences , Nanjing , China
| | - Błażej Bojarski
- Laboratory of Evolutionary Entomology and Museum of Amber Inclusions, Department of Invertebrate Zoology and Parasitology, Faculty of Biology, University of Gdansk , Gdansk , Poland
| | - Jacek Szwedo
- Laboratory of Evolutionary Entomology and Museum of Amber Inclusions, Department of Invertebrate Zoology and Parasitology, Faculty of Biology, University of Gdansk , Gdansk , Poland
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9
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Sutton GP, St Pierre R, Kuo CY, Summers AP, Bergbreiter S, Cox S, Patek SN. Dual spring force couples yield multifunctionality and ultrafast, precision rotation in tiny biomechanical systems. J Exp Biol 2022; 225:275995. [PMID: 35863219 DOI: 10.1242/jeb.244077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 06/15/2022] [Indexed: 12/31/2022]
Abstract
Small organisms use propulsive springs rather than muscles to repeatedly actuate high acceleration movements, even when constrained to tiny displacements and limited by inertial forces. Through integration of a large kinematic dataset, measurements of elastic recoil, energetic math modeling and dynamic math modeling, we tested how trap-jaw ants (Odontomachus brunneus) utilize multiple elastic structures to develop ultrafast and precise mandible rotations at small scales. We found that O. brunneus develops torque on each mandible using an intriguing configuration of two springs: their elastic head capsule recoils to push and the recoiling muscle-apodeme unit tugs on each mandible. Mandibles achieved precise, planar, circular trajectories up to 49,100 rad s-1 (470,000 rpm) when powered by spring propulsion. Once spring propulsion ended, the mandibles moved with unconstrained and oscillatory rotation. We term this mechanism a 'dual spring force couple', meaning that two springs deliver energy at two locations to develop torque. Dynamic modeling revealed that dual spring force couples reduce the need for joint constraints and thereby reduce dissipative joint losses, which is essential to the repeated use of ultrafast, small systems. Dual spring force couples enable multifunctionality: trap-jaw ants use the same mechanical system to produce ultrafast, planar strikes driven by propulsive springs and for generating slow, multi-degrees of freedom mandible manipulations using muscles, rather than springs, to directly actuate the movement. Dual spring force couples are found in other systems and are likely widespread in biology. These principles can be incorporated into microrobotics to improve multifunctionality, precision and longevity of ultrafast systems.
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Affiliation(s)
- Gregory P Sutton
- School of Life Sciences , University of Lincoln, Lincoln LN6 7TS, UK
| | - Ryan St Pierre
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14260, USA
| | - Chi-Yun Kuo
- Biology Department, Duke University, Durham, NC 27708, USA
| | - Adam P Summers
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
| | - Sarah Bergbreiter
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Suzanne Cox
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14260, USA
| | - S N Patek
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14260, USA
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10
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Casadei‐Ferreira A, Feitosa RM, Pie MR. Size and shape in the evolution of the worker head in
Pheidole
ants (Hymenoptera: Formicidae). J Zool (1987) 2022. [DOI: 10.1111/jzo.12978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. Casadei‐Ferreira
- Departamento de Zoologia Setor de Ciências Biológicas Centro Politécnico Universidade Federal do Paraná Curitiba Paraná Brazil
- Biodiversity and Biocomplexity Unit Okinawa Institute of Science and Technology Graduate University Onna Okinawa Japan
| | - R. M. Feitosa
- Departamento de Zoologia Setor de Ciências Biológicas Centro Politécnico Universidade Federal do Paraná Curitiba Paraná Brazil
| | - M. R. Pie
- Departamento de Zoologia Setor de Ciências Biológicas Centro Politécnico Universidade Federal do Paraná Curitiba Paraná Brazil
- Biology Department Edge Hill University Ormskirk Lancashire UK
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11
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Lieberman ZE, Billen J, Kamp T, Boudinot BE. The ant abdomen: the skeletomuscular and soft tissue anatomy of
Amblyopone australis
workers (Hymenoptera: Formicidae). J Morphol 2022; 283:693-770. [DOI: 10.1002/jmor.21471] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 02/28/2022] [Accepted: 03/09/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Ziv Ellis Lieberman
- Department of Entomology and Nematology University of California Davis, One Shields Ave, Davis, CA, U. S. A. 95616
| | - Johan Billen
- Zoological Institute, University of Leuven, Naamsestraat 59, Box 2466, B‐3000 Leuven Belgium
| | - Thomas Kamp
- Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), Hermann‐von‐Helmholtz‐Platz 1, 76344 Eggenstein‐Leopoldshafen Germany
- Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), Kaiserstraße 12 Karlsruhe Germany
| | - Brendon Elias Boudinot
- Friedrich‐Schiller‐Universität Jena, Institut für Spezielle Zoologie und Evolutionsforschung, Entomologie Gruppe, Erbertstraße 1 07743 Jena Germany
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12
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Boudinot BE, Richter A, Katzke J, Chaul JCM, Keller RA, Economo EP, Beutel RG, Yamamoto S. Evidence for the evolution of eusociality in stem ants and a systematic revision of †Gerontoformica (Hymenoptera: Formicidae). Zool J Linn Soc 2022. [DOI: 10.1093/zoolinnean/zlab097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
It is generally assumed that Cretaceous stem ants were obligately eusocial, because of the presence of wingless adult females, yet the available evidence is ambiguous. Here, we report the syninclusion of a pupa and adult of a stem ant species from Mid-Cretaceous amber. As brood are immobile, the pupa was likely to have been transported by an adult. Therefore, the fossil substantiates the hypothesis that wingless females were cooperators, thus these were true ‘workers’. Re-examination of all described Cretaceous ant species reveals that winged–wingless diphenism – hence a variable dispersal capacity – may have been ancestral to the total clade of the ants, and that highly specialized worker-specific phenotypes evolved in parallel between the stem and crown groups. The soft-tissue preservation of the fossil is exceptional, demonstrating the possibility of analysing the development of the internal anatomy in stem ants. Based on the highest-resolution µ-CT scans of stem ants to date, we describe †Gerontoformica sternorhabda sp. nov., redescribe †G. gracilis, redefine the species group classification of †Gerontoformica, and provide a key to the species of the genus. Our work clarifies the species boundaries of †Gerontoformica and renders fossils relevant to the discussion of eusocial evolution in a way that has heretofore been intractable.
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Affiliation(s)
- Brendon E Boudinot
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Erberstraße 1, 07743 Jena, Germany
| | - Adrian Richter
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Erberstraße 1, 07743 Jena, Germany
| | - Julian Katzke
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Júlio C M Chaul
- Pós-Graduação em Ecologia, Departamento de Biologia Geral, Universidade Federal do Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil
| | - Roberto A Keller
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
- Museu Nacional de História Natural e da Ciência & cE3c, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisbon, Portugal
| | - Evan P Economo
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Rolf Georg Beutel
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Erberstraße 1, 07743 Jena, Germany
| | - Shûhei Yamamoto
- Hokkaido University Museum, Hokkaido University, Kita 8, Nishi 5, Kita-ku, Sapporo 060-0808, Japan
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13
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Esteves FA, Fisher BL. Corrieoponenouragues gen. nov., sp. nov., a new Ponerinae from French Guiana (Hymenoptera, Formicidae). Zookeys 2022; 1074:83-173. [PMID: 34975267 PMCID: PMC8671710 DOI: 10.3897/zookeys.1074.75551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/13/2021] [Indexed: 11/26/2022] Open
Abstract
This study describes the worker and queen castes of the Neotropical ponerine Corrieoponenouraguesgen. nov., sp. nov., an ant from the tropical rainforest in French Guiana. Worker morphology of the taxon is compared with those of other Ponerinae and the similarities between them are discussed, refining the definition of character states for some diagnostic characters at the generic level, providing an identification key to the Neotropical genera, and making some adjustments to the taxonomic framework within the subfamily. Descriptions, diagnosis, character discussion, identification key, and glossary are illustrated with more than 300 images and line drawings. Open science is supported by providing access to measurement data for specimens of the new genus, a matrix of character states for all ponerine taxa evaluated in this study, and specimen data for all examined material. The new or revived combinations presented here are Pachycondylaprocidua Emery, comb. rev., Neoponeracuriosa (Mackay and Mackay), comb. nov., Leptogenysbutteli (Forel), comb. nov., and Bothroponeraescherichi (Forel), comb. nov. In addition, Leptogenysbutteli is synonymized with Leptogenysmyops (Emery), syn. nov.
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Affiliation(s)
- Flavia A Esteves
- Entomology, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA California Academy of Sciences San Francisco United States of America
| | - Brian L Fisher
- Entomology, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA California Academy of Sciences San Francisco United States of America
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