scholarly journals Evolutionary morphology of the antennal heart in stick and leaf insects (Phasmatodea) and webspinners (Embioptera) (Insecta: Eukinolabia)

Zoomorphology ◽  
2021 ◽  
Author(s):  
Benjamin Wipfler ◽  
Sven Bradler ◽  
Sebastian Büsse ◽  
Jörg Hammel ◽  
Bernd R. Müller ◽  
...  

AbstractThe morphology of the antennal hearts in the head of Phasmatodea and Embioptera was investigated with particular reference to phylogenetically relevant key taxa. The antennal circulatory organs of all examined species have the same basic construction: they consist of antennal vessels that are connected to ampullae located in the head near the antenna base. The ampullae are pulsatile due to associated muscles, but the points of attachment differ between the species studied. All examined Phasmatodea species have a Musculus (M.) interampullaris which extends between the two ampullae plus a M. ampulloaorticus that runs from the ampullae to the anterior end of the aorta; upon contraction, all these muscles dilate the lumina of both ampullae at the same time. In Embioptera, only the australembiid Metoligotoma has an M. interampullaris. All other studied webspinners instead have a M. ampullofrontalis which extends between the ampullae and the frontal region of the head capsule; these species do not have M. ampulloaorticus. Outgroup comparison indicates that an antennal heart with a M. interampullaris is the plesiomorphic character state among Embioptera and the likely ground pattern of the taxon Eukinolabia. Antennal hearts with a M. ampullofrontalis represent a derived condition that occurs among insects only in some embiopterans. These findings help to further clarify the controversially discussed internal phylogeny of webspinners by supporting the view that Australembiidae are the sister group of the remaining Embioptera.

Zootaxa ◽  
2008 ◽  
Vol 1817 (1) ◽  
pp. 49 ◽  
Author(s):  
VASILY V. GREBENNIKOV ◽  
ALFRED F. NEWTON

External morphology of larvae belonging to three unidentified genera of the rove-beetle subfamily Leptotyphlinae (Coleoptera: Staphylinidae) collected in Mexico, Chile and Australia, respectively, is described and illustrated. Larvae of Leptotyphlinae can be distinguished from all other Staphylinoidea larvae by the combination of their small size (maximum documented head width 0.128 mm), along with complete absence of eyes, lyriform frontal ecdysial lines, long coronal suture extending for about 40% of head length, short antennae not longer than 1/3 of head length, non-serrate mandibles with a single pre-apical tooth, tibiotarsi swollen in middle with two ventral spines, and indistinctly articulated short urogomphi not longer than twice their basal width. At least some of these characters are likely to support monophyly of the subfamily. Leptotyphlinae are hypothesized to belong to the Staphylinine Group of subfamilies sharing with at least some of them the following larval characters: labrum fully fused with clypeus; posterior tentorial arms extremely thin, thread-like and more than 20 times longer than wide; posterior tentorial pits short, rounded to elongate; cardo lacking transverse sclerotized ridge. The sister-group relationships of Leptotyphlinae to a clade of Pseudopsinae+Paederinae+Staphylininae is hypothesized with the following larval characters in support: lyriform frontal arms; each maxilla articulated laterally to head capsule by a condyle; maxillary mala parallel-sided (=finger-shaped) and articulated to stipes. A larval identification key to all three presently described genera is given.


1990 ◽  
Vol 68 (3) ◽  
pp. 556-578 ◽  
Author(s):  
Gregory W. Courtney

The cuticular structure of larval mountain midges (Diptera: Deuterophlebiidae) is described, with emphasis on cranial and mouthpart morphology. Homologies are suggested for musculature and external features of the head capsule. External morphology of the thorax and abdomen is described, and a system for deuterophlebiid larval chaetotaxy is presented. Also included is a discussion of the feeding behaviour of deuterophlebiid and blepharicerid larvae, and how differing morphological characteristics influence mechanisms of food acquisition. Larval morphology of the Deuterophlebiidae and other Nematocera provides support for (i) a sister-group relationship between the Deuterophlebiidae and Blephariceridae; (ii) a monophyletic Blephariceromorpha (sensu Wood and Borkent) composed of the Nymphomyiidae + (Deuterophlebiidae + Blephariceridae); and (iii) a sister-group relationship between the Blephariceromorpha and Psychodomorpha (sensu Wood and Borkent).


1985 ◽  
Vol 63 (4) ◽  
pp. 933-955 ◽  
Author(s):  
Jarmila Kukalová-Peck

Gigantic as well as very large mayflies from the middle Upper Carboniferous (Westphalian) strata of Europe and North America are described: the adult and nymph of Bojophlebia prokopi n. gen., n. sp. (Bojophlebiidae n. fam.) and the nymphs of Lithoneura piecko n. sp. and Lithoneura clayesi n. sp. (Syntonopteridae). Evolution of ephemerid wing venation during 300 million years is summarized. Autapomorphic, apomorphic, and plesiomorphic character states of venation are categorized. Venational nomenclature of Recent Ephemerida is emended based on its evolutionary changes. Evidence that wing veins occurred primitively as a pair of fluted sectors is documented in Carboniferous mayflies in the costa, subcosta, radius, anal, and jugal. Ephemeroids and odonatoids are sister groups that share the veinal anal brace AA fused with CuP at an area important for flight. Ancestral Odonatoephemerida are the sister group of the extinct haustellate Paleoptera. The Carboniferous nymphs bear three pairs of almost homonomous thoracic wings and, on the abdomen, nine pairs of legs and nine pairs of tracheal gills (wing homologues). This proves that abdominal legs have been totally reduced in Recent Ephemerida except for the claspers (gonopods) and that tracheal gills are not flattened legs. The metamorphic instar probably originated in relatively young instars. Insectan cerci developed from segmented, arched, functional legs of abdominal segment 11, which were still present in this primitive condition in Carboniferous Monura.


1986 ◽  
Vol 118 (3) ◽  
pp. 205-240 ◽  
Author(s):  
Gary A.P. Gibson

AbstractTwenty-three characters or character systems of adults and larvae of Terebrantes are analyzed for evidence of monophyly and phyletic relationships of Chalcidoidea, Mymaridae, and Mymarommatidae. The taxa are considered to be a monophyletic group based on 3 hypothesized synapomorphies: mesotrochanteral depressor without fu2-tr2 or mesoscutal portion of t2-tr2; axillar phragma as site of origin for all or part of t,-tr2 muscle; and independent basal ring absent from male genitalia. The family Mymaridae is considered to be monophyletic based on at least 3 apomorphies: fore wing with hypochaeta; head with frontal, median, and supraorbital sulci; and toruli distinctly closer to inner margin of eye than to each other. Chalcidoidea, including Mymaridae, is considered to be a monophyletic taxon based on 3 apomorphies: prepectus externally visible, at least dorsally adjacent to lateral edge of mesoscutum; mesothoracic spiracle positioned at exposed lateral edge of mesoscutum; and multiporous plate sensilla of antenna with unique structure, as described in text. Mymarommatidae is considered to be the monophyletic sister group of Chalcidoidea based on several apomorphies, including 4 autapomorphies: head composed of frontal and occipital sclerites, which are connected by pleated membrane along hyperoccipital region; hind wing stalk-like, without membrane and terminated in bifurcation that clasps fore wing; fore wing with reticulate pattern formed by raised lineations of membrane; and axillar portion of t2-tr2 muscle absent. Phyletic relationship of Serphitidae with Mymarommatidae is deemed inconclusive because relevant internal character states of amber fossil serphitids cannot be determined. It is suggested that mymarommatids be accorded family status, but not be assigned to superfamily until phyletic relationships are more accurately determined in Terebrantes. A matrix summarizes character-state distribution of most characters analyzed for Terebrantes, and a cladogram illustrates hypotheses of character-state evolution and proposed relationships.


1991 ◽  
Vol 65 (2) ◽  
pp. 314-322 ◽  
Author(s):  
Robert L. Carroll ◽  
Paul Bybee ◽  
William D. Tidwell

Utaherpeton franklini n. gen. and sp., from the Manning Canyon Shale Formation of Utah, is the oldest known microsaur. The horizon is dated as equivalent to the lowermost Namurian B of Europe (transitional from Upper Mississippian into lowermost Pennsylvanian in North American terminology) on the basis of a rich assemblage of fossil plants. The specimen may be tentatively placed within the suborder Microbrachomorpha. It exhibits the primitive character state for many microsaur features, but no synapomorphies are recognized that support a specific sister-group relationship between microsaurs and any other group of Paleozoic tetrapods.


2000 ◽  
Vol 14 (6) ◽  
pp. 825 ◽  
Author(s):  
Rolf G. Beutel ◽  
Darren A. Pollock

The larval head of a Phycosecis species is described and illustrated. Characters are compared to those found in larvae of other groups of Cucujiformia. Monophyly of all cleroid families examined is supported by several apomorphic features at least partly correlated with predacious habits: antennae directed anteriad, absence of the mandibular mola, presence of a pedunculate seta on the mala, presence of a median endocarina, origin of antennal muscles exclusively from the head capsule, and presence of a weakly pigmented, parallel-sided gular plate. A possible apomorphy of Cleroidea excluding Phloiophilidae is the parallel-sided, prognathous head. A sister-group relationship between Phycosecidae and Melyridae is supported by the presence of a plumose lacinia mobilis and secondary loss of the median endocarina. A monophylum comprising Cleridae + Chaetosomatidae is characterised by a strongly elongated, sclerotised larval gula, the strongly protracted position of the ventral mouthparts, and a cardo as long as or longer than the stipes. Monophyly of Trogossitidae is only weakly supported. Several apomorphies indicate a sister-group relationship between Cleroidea and Nitidulidae. These two taxa are characterised by a fully developed maxillolabial complex, an elongated prepharyngeal tube, and tergal sclerotisation restricted to the prothorax and tergite IX. A tentorial bridge completely separated from the remaining tentorium, and a maxillolabial complex with partly restricted motility of the maxilla are shared derived features of larvae of Cleroidea, Nitidulidae, Coccinellidae and Endomychidae. An unusual attachment of a part of the tentoriostipital muscle to the floor of the prepharyngeal tube is found in all cleroid and cucujoid larvae examined. Cleroidea are a well-defined monophyletic group and may form a monophylum together with a paraphyletic assemblage of Cucujoidea. A close relationship between Cleroidea and Lymexylidae is refuted.


<em>Abstract</em>.-We develop the view, based on life cycle differences and recently published sister group relationships, that the freshwater life cycle was the ancestral character state leading to anadromy among salmoniforms, whereas the marine life cycle was the ancestral character state leading to anadromy among osmeriforms. In contrast to most salmonid fishes, the reproductive migrations of smelts are generally characterized by brief excursions to spawn in freshwater, and larvae may spend no more than 24 h in freshwater before being transported to coastal marine or estuarine environments. We reconstructed the phylogeny of the suborder Osmeroidei to establish the phylogenetic relationships among anadromous, marine, and freshwater species of this taxon. We mapped these life cycles onto phylogenetic trees of osmeriforms and salmoniforms and applied character-reconstruction methodology based on simple parsimony and likelihood methodologies. A freshwater origin of salmonids was supported by our analyses, whereas either marine or anadromous life cycles characterized the evolution of osmeroids. The possibility that the evolution of anadromy in salmonids and osmeroids followed separate paths requires a reconsideration of some generalizations concerning anadromy. We hypothesize that anadromy in osmeroids may be first and foremost an adaptation to place embryos and the early larval stages in reproductive safe sites to maximize their survival. The evolution of exclusive freshwater species of osmeriforms has occurred via anadromy through the various processes associated with landlocking. Freshwater amphidromy in osmeroids is most likely a consequence of anadromy rather than a precursor and may be contingent upon the availability of food resources in freshwater. Finally, marine osmeroids have been derived from anadromous ancestors and are "safe-site" specialists, exploiting principally the upper intertidal zone for reproduction. We also suggest that such contrasting evolutionary pathways to anadromy may provide insight into the evolution of partial migration, observed uniquely in salmonids, and the nature and extent of population genetic structure found in the two groups of fishes.


1995 ◽  
Vol 26 (2) ◽  
pp. 229-239 ◽  
Author(s):  
Michael Balke

AbstractRhantus rugulosus Régimbart, 1899, R. rohani Peschet, 1924, R. colymbitoides Gschwendtner, 1932 and R. tigris sp. n. form a monophyletic group, here referred to as the R. rugulosus-clade. The ground pattern of this group is discussed, and the species are briefly described. R. rugulosus + R. tigris is the sister group of R. rohani + R. colymbitoides. The former is Oriental, the latter Afrotropical. The extant distribution range of the R. rugulosus-clade, i.e., a disjunct range with species occurring either in the Oriental or the Afrotropical region, is explained by Miocene dispersal and late Cenozoic vicariance events.


1984 ◽  
Vol 116 (S128) ◽  
pp. 5-270 ◽  
Author(s):  
Art Borkent

AbstractThe Stenochironomus complex contains all those species which exhibit the highly modified, mining larval form previously recognized as typical of only the genus Stenochironomus Kieffer: larvae with a dorsoventrally compressed head capsule, expanded thoracic segments and a long, flaccid abdomen. The complex includes members of Xestochironomus Sublette & Wirth (New World), Harrisius Freeman (Australian Region), Stenochironomus (cosmopolitan) and two larval forms, one from New Zealand and the other from Africa.This revision provides analysis of 12 species of Xestochironomus (five new), four species of Harrisius, and 54 species of Neotropical and Holarctic Stenochironomus (32 new named species, two new species not named, and four new combinations: S. innocuus (Williston), S. semifumosus (Edwards), S. longilobatus (Tokunaga) and S. gracilivalva (Kieffer)). Of these species, the pupae and fourth instar larvae are described for two species of Xestochironomus, Harrisius pallidus Freeman and 24 of the named species of Stenochironomus. Descriptions, diagnoses, keys, and distribution maps are provided for all species in each available stage. Stenochironomus taeniapennis (Coquillett, 1901), S. zonopterus (Mitchell, 1908), and S. exquisitus (Mitchell, 1908) are newly recognized as junior synonyms of S. hilaris (Walker, 1848).A cladistic analysis of all these species suggests that the Stenochironomus complex is monophyletic. The African larval form is the sister group of all other members; Xestochironomus is the sister group of Harrisius, the New Zealand larval form and Stenochironomus; and Stenochironomus is the sister group of Harrisius plus the New Zealand larval form. These relationships suggest possible southern continental affinities. Stenochironomus is composed of two monophyletic species groups, the subgenus Stenochironomus s. str. with species whose larvae mine wood and the new subgenus Petalopholeus (type-species, S. cinctus Townes) with species whose larvae mine leaves.Cladistic patterns show that Caribbean species are related to other New World species, and that North American species are related to Neotropical or Palaearctic species.Larval food type and ecological differences are analyzed using cladistic relationships. The plesiotypic habitat for species of the Stenochironomus complex is running waters.The phylogenetic relationships of Stenochironomus species and their mite parasites are compared and show little congruence.


2020 ◽  
Vol 117 (16) ◽  
pp. 8966-8972 ◽  
Author(s):  
Gregory D. Edgecombe ◽  
Christine Strullu-Derrien ◽  
Tomasz Góral ◽  
Alexander J. Hetherington ◽  
Christine Thompson ◽  
...  

Identifying marine or freshwater fossils that belong to the stem groups of the major terrestrial arthropod radiations is a longstanding challenge. Molecular dating and fossils of their pancrustacean sister group predict that myriapods originated in the Cambrian, much earlier than their oldest known fossils, but uncertainty about stem group Myriapoda confounds efforts to resolve the timing of the group’s terrestrialization. Among a small set of candidates for membership in the stem group of Myriapoda, the Cambrian to Triassic euthycarcinoids have repeatedly been singled out. The only known Devonian euthycarcinoid, Heterocrania rhyniensis from the Rhynie and Windyfield cherts hot spring complex in Scotland, reveals details of head structures that constrain the evolutionary position of euthycarcinoids. The head capsule houses an anterior cuticular tentorium, a feature uniquely shared by myriapods and hexapods. Confocal microscopy recovers myriapod-like characters of the preoral chamber, such as a prominent hypopharynx supported by tentorial bars and superlinguae between the mandibles and hypopharynx, reinforcing an alliance between euthycarcinoids and myriapods recovered in recent phylogenetic analysis. The Cambrian occurrence of the earliest euthycarcinoids supplies the oldest compelling evidence for an aquatic stem group for either Myriapoda or Hexapoda, previously a lacuna in the body fossil record of these otherwise terrestrial lineages until the Silurian and Devonian, respectively. The trace fossil record of euthycarcinoids in the Cambrian and Ordovician reveals amphibious locomotion in tidal environments and fills a gap between molecular estimates for myriapod origins in the Cambrian and a post-Ordovician crown group fossil record.


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