Esophyllas Prentice & Redak, 2012, new genus
Creators: name: Prentice, Thomas R.
name: Redak, Richard A.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Esophyllas

description: Esophyllas new genus
Type species. Esophyllas vetteri new species
Etymology. The name is derived from the Greek language and is feminine in gender, the prefix eso- meaning ‘within’ and phyllas meaning ‘bed of leaves’, referring to the habitat from which almost all specimens were collected, more specifically, oak leaf litter.
Diagnosis. Esophyllas n. gen. is composed of two small desmitracheate (taenidia absent; Blest 1976) species with short emboli and is distinguished from all genera in the ‘ Tapinocyba group’ (Millidge 1977; following current placement: Tapinocyba, Phlattothrata, Crosbyarachne Charitonov 1937, Ceratinops Banks, Mecynargus Kulczin’ski, Semljicola Strand, Thyreosthenius Simon, Acartauchenius Simon, Trichopternoides thorelli (Westring), and Erigonoplus Simon) and Scirites by the following male characters: presence of post-PME cephalic lobe (also in Phlattothrata and Tapinocyba prima Dupérré & Paquin 2005), absence of the protegulum, a strong proximal to distal contraction of the tegulum (Figs 8, 28: T), a tubular sclerotized column (Figs 6, 26: CL; also present in P. parva), sperm duct looped over the embolic division (ED) prior to entering the radix on the proximomesal side of the ED (Figs 7, 27: R), entry further posteriad and closer to the middle of the bulb (Figs 6, 26; loop and entry similar in Crosbyarachne silvestris (Georgescu 1973) but column is membranous and carries an embolic membrane), tibial spine arrangement of 2-2-1-1 (vs. 1-1-1-1, 2-2-2-1, or in Erigonoplus, 2-2-1-1), proximal to distal orientation of the paracymbium (length greater than width, Figs 8, 28: P; similar in P. parva), and presence of a flat triangular process projecting from the dorsal edge of the paracymbium (Figs 8, 28: P) and a heavily sclerotized refexed barb forming the terminus of the tibial apophysis (Figs 7, 8, 27, 28: PTA). The latter two characters are considered to be synapomorphies of Esophyllas n. gen.
Males are further separated from those of four of the above genera (Tapinocyba, Phlattothrata, Crosbyarachne, Scirites), with which Esophyllas n. gen. is believed to be more closely related, by the following: from Tapinocyba by the absence of pectinate tarsal claws, a dorsal seta on the palpal patella, a prolateral trichobothria on the palpal tibia, and a sudden constriction in the diameter of the sperm duct; from P. p ar v a by the absence of an anterior radical process, an embolic membrane (SEM imaging necessary to confirm attachment points in P. pa r v a; not a permitted option for borrowed material), pectinate tarsal claws, and a prolateral trichobothria on the palpal tibia (Figs 7, 27), and by the position of the lateral sulci and prosomal pits (Figs 1, 21; compare to Paquin & Dupérré 2003; fig 1273, P. flagellata (Emerton)); from Crosbyarachne by the presence of a short straight embolus (vs. long and coiled), absence of an embolic membrane, a sudden constriction in the diameter of the sperm duct, pectinate tarsal claws, and a prolateral trichobothrium on the palpal tibia, and by the patterned abdomen; from Scirites by the absence of a row of strong megaspines on metatarsus I and papillae on the tegulum, pleurites and sternite of the male pedicel not juxtaposed, the presence of lateral sulci, prosomal pits, and patterned abdomen (Figs 1, 5, 21, 25).
Females are most easily confused with Spirembolus pusillus Millidge and S. novellus Millidge (refer to Millidge 1980b) that have similar epigynal morphology, abdominal patterning and distributions (either overlapping or closely adjacent) and can be distinguished by the smaller size, greater width between the ectal margins of the spermathecae than the width of the dorsal plate (Figs 11, 30: S, DP), convolution of the copulatory ducts only on the mesal side of the spermathecae (Figs 12, 31: CD), copulatory ducts with only a single loop prior to entering the spermathcae on the mesal side (Figs 12, 31: CD), TmI 0.30–0.40, and tibial spine arrangement of 2-2-1-1.
Description. Small desmitracheate (taenidia absent; Blest 1976) erigonines with males ranging in total length from 1.05–1.25 and females from 1.15–1.60, TmI 0.31–0.41, TmIV absent, tibial spines 2-2-1-1, stridulatory mechanisms on both the chelicerae (Figs 13, 19, 32, 36) and booklung plates (Figs 14, 20, 33, 37), yellowishorange color of the carapace, chelicerae, sternum, and legs, and a dark abdominal herringbone pattern (Figs 5, 25). Males are further recognized by the post-PME cephalic lobe with lateral sulci and prosomal pits (Figs 1, 21), the ED consisting of a short straight embolus with spiraled and grooved terminus (Figs 16, 35: E), very short tailpiece (Figs 6, 26: TP), with the sperm duct looped over the ED through a sclerotized tubular column prior to entering the radix on the mesal surface of the ED near the middle of the bulb (Figs 7, 27: CL, R). The tegulum strongly is compressed between proximal and distal margins (Figs 8, 28: T) and both the protegulum and embolic membrane are absent; the membrane that is present is articulated with only the distal suprategular apophysis (Figs 6, 16, 26, 35: M, DSA) and not considered an embolic membrane (see Hormiga 1994). The tarsal claws are smooth and not pectinate, the orientation of the flattened inverted J-shaped the paracymbium (Figs 8, 28: P) is proximal to distal (longer than wide), a flat triangular process projects from the dorsal surface of the paracymbium (Figs 8, 28: P), and the palpal tibial apophysis terminates in a heavily sclerotized refexed barb (Figs 7, 8, 27, 28, 29: PTA). Females are further recognized by relatively large clearly visible orangish-yellow spermathecae with posterior margins positioned anterior to the copulatory openings and by the greater width between the ectal margins of the spermathecae than the greatest width of the triangular dorsal plate (Figs 11, 30: S, CO, DP).
description: Published as part of Prentice, Thomas R. & Redak, Richard A., 2012, Esophyllas, a new genus of erigonine spiders from southern California (Araneae: Linyphiidae: Erigoninae), pp. 1-21 in Zootaxa 3265 on pages 3-4, DOI: 10.5281/zenodo.213135