Lyroconus plagioptycha
Creators: name: Gargominy, Olivier
name: Fontaine, Benoît
name: Tercerie, Sandrine
name: Zuccon, Dario
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Thysanophoridae
Lyroconus
Lyroconus plagioptycha

description: Lyroconus plagioptycha (Shuttleworth, 1854)
Figs 8, 9
Helix plagioptycha Shuttleworth, 1854: 37.
Thysanophora plagioptycha (Shuttleworth, 1854) — Pilsbry (1920): 94, figs 2, 3.
Lyroconus plagioptycha (Shuttleworth, 1854) — Schileyko (2006): 1896.
Link.
https://molluscabase.org/aphia.php?p=taxdetails&id=1065439.
Material examined.
French Guiana • 1 dry specimen; Régina, Montagne Favard (Montagne de Kaw), ca 200 m sur le chemin W depuis la fin de la route (dégrad) D 6 (COT 03); 4.5 ° N, 52.05722 ° W; 20 Oct. 1997; TR, OG leg.; Petit ruisseau, forêt; MNHN -IM-2012-21187 • 1 dry specimen; Remire-Montjoly, Lotissement DDE, 1.4 km sur la route des plages (D 1) après le carrefour de Dégrad des Cannes, Montagne du Mahury (COT 06); 4.86056 ° N, 52.25917 ° W; alt. 15 m; 21 Oct. 1997; TR, OG leg.; culture de bananes et papayes; MNHN -IM-2012-23924 • 3 dry specimens; Roura, Crique Sourou, Rte forestière de Nancibo (COT 10); 4.67273 ° N, 52.42825 ° W; alt. 10 m; 23 Oct. 1997; TR, OG leg.; ripisylve, sol alluvial; MNHN -IM-2022-2131 • 1 dry specimen; Saint-Laurent-du-Maroni, Rte du Plateau des cascades, plateau des mines, 3.7 km après la D 11 (COT 27); 5.38569 ° N, 54.06283 ° W; 28 Oct. 1997; TR, OG leg.; reste de forêt sur une route bordée de parcelles conquises sur la forêt; MNHN -IM-2022-2130 • 1 dry specimen; Sinnamary, Petit Saut, 1.4 km avant le rond-point “ barrage du Petit Saut ” (COT 30); 5.06111 ° N, 52.99778 ° W; 28 Oct. 1997; TR, OG leg.; forêt dense, fond de talweg; MNHN -IM-2022-2137 • 24 dry specimens; Saül (SAUL 25); 3.61274 ° N, 53.21626 ° W; alt. 174 m; 17 Nov. 2018; OG, SS, ST, BF (PAG & MNHN) leg.; Pied d’arbre à contrefort; MNHN -IM-2012-21932 • 5 95 % ethanol specimens; Saül (SAUL 25); 3.61274 ° N, 53.21626 ° W; alt. 174 m; 17 Nov. 2018; OG, SS, ST, BF (PAG & MNHN) leg.; Pied d’arbre à contrefort; MNHN -IM-2013-75621 • 2 dry specimens; Saül (SAUL 37); 3.63555 ° N, 53.21035 ° W; alt. 276 m; 21 Nov. 2018; OG, SS, ST, BF (PAG & MNHN) leg.; Autour d’un arbre à contreforts; MNHN -IM-2012-21956 • 2 95 % ethanol specimens; Saül (SAUL 37); 3.63555 ° N, 53.21035 ° W; alt. 276 m; 21 Nov. 2018; OG, SS, ST, BF (PAG & MNHN) leg.; Autour d’un arbre à contreforts; MNHN -IM-2013-75655 • 4 dry specimens; Saül, Versant nord de Bœuf Mort, le long du sentier de Grand Bœuf Mort (SAUL 44); 3.64098 ° N, 53.21863 ° W; alt. 300 m; 24 Nov. 2018; OG, SS, ST, BF (PAG & MNHN) leg.; Pied d’arbre à contreforts; MNHN -IM-2012-21965 • 1 95 % ethanol specimen; Saül, Cascades au pied du Galbao (SAUL 49); 3.60254 ° N, 53.26051 ° W; alt. 220 m; 29 Nov. 2018; OG, SS, ST, BF (PAG & MNHN) leg.; Chaos rocheux; GenBank: PQ 629103; Bold: DREAL 353-23; MNHN -IM-2013-75961 • 1 dry specimen; Saül, Cascades au pied du Galbao (SAUL 49); 3.60254 ° N, 53.26051 ° W; alt. 220 m; 29 Nov. 2018; OG, SS, ST, BF (PAG & MNHN) leg.; Chaos rocheux; MNHN -IM-2018-677 • 1 95 % ethanol specimen; Mana, Layon C vers 1900 m (TRI 19); 4.583 ° N, 53.40587 ° W; alt. 50 m; 14 Apr. 2019; BF, ST (MNHN / ONF) leg.; forêt de lianes; GenBank: PQ 629104; Bold: DREAL 358-23; MNHN -IM-2013-75993 • 1 95 % ethanol specimen; Mana, cambrouse layon C à environ 1300 m du camp Aya (TRI 20); 4.58417 ° N, 53.4054 ° W; alt. 80 m; 14 Apr. 2019; BF, ST (MNHN / ONF) leg.; Cambrouse; MNHN -IM-2013-75819 • 3 dry specimens; same data as preceding; MNHN -IM-2014-7922 • 2 dry specimens; Mana, Layon inselberg 120 m (pente inselberg) (TRI 21); 4.61157 ° N, 53.40833 ° W; alt. 180 m; 15 Apr. 2019; BF, ST (MNHN / ONF) leg.; pied de rochers granitiques; MNHN -IM-2014-7923 • 1 95 % ethanol specimen; Mana, Réserve naturelle de La Trinité, Layon C à environ 1600 m du camp Aya (TRI 31); 4.58421 ° N, 53.40542 ° W; alt. 67 m; 18 Apr. 2019; BF, ST (MNHN / ONF) leg.; Cambrouse; GenBank: PQ 629101; Bold: DREAL 364-23; MNHN -IM-2013-75992 • 1 95 % ethanol specimen; Mana, Réserve naturelle de La Trinité, Layon C à environ 1600 m du camp Aya (TRI 31); 4.58421 ° N, 53.40542 ° W; alt. 67 m; 18 Apr. 2019; BF, ST (MNHN / ONF) leg.; Cambrouse; MNHN -IM-2013-75820 • 12 dry specimens; Mana, Réserve naturelle de La Trinité, Layon C à environ 1600 m du camp Aya (TRI 31); 4.58421 ° N, 53.40542 ° W; alt. 67 m; 18 Apr. 2019; BF, ST (MNHN / ONF) leg.; Cambrouse; MNHN -IM-2014-7924 • 2 dry specimens; Saül, Chemin des Monts la Fumée (SAUL 63); 3.63119 ° N, 53.20586 ° W; alt. 177 m; 18 Feb. 2020; BF, AA, OG (PAG & MNHN) leg.; Pied d’arbre à contrefort; MNHN -IM-2018-14083 • 1 dry specimen; Saül, Cascades du Mont Galbao, face nord-est (SAUL 64); 3.60376 ° N, 53.26121 ° W; alt. 320 m; 19 Feb. 2020; BF, AA, OG (PAG & MNHN) leg.; Bordure de cambrouse; MNHN -IM-2018-14067 • 3 dry specimens; Saül, Mont Galbao face nord-est (SAUL 65); 3.59681 ° N, 53.26257 ° W; alt. 503 m; 20 Feb. 2020; BF, AA, OG (PAG & MNHN) leg.; Cambrouse et lianes en forêt; MNHN -IM-2018-14051 • 1 95 % ethanol specimen; Saül, Mont Galbao face nord-est (SAUL 65); 3.59681 ° N, 53.26257 ° W; alt. 503 m; 20 Feb. 2020; BF, AA, OG (PAG & MNHN) leg.; Cambrouse et lianes en forêt; MNHN -IM-2013-76405 • 1 dry specimen; Saül (SAUL 70); 3.60864 ° N, 53.21492 ° W; alt. 212 m; 23 Feb. 2020; BF, AA, OG (PAG & MNHN) leg.; MNHN -IM-2018-14120.
Remarks.
All specimens collected in French Guiana are consistent with the diagnosis by Pilsbry (1920) and the illustration of syntype NMBE 18878 figured in Neubert and Gosteli (2003: pl. 20 fig. 4).
Lyroconus plagioptycha (type locality Puerto Rico) is a widespread species in Greater Antilles and Central America from Florida to Venezuela (https://www.gbif.org/species/5190501), and was recently recorded in northeastern Brazil (Salvador et al. 2021). It was reported from Suriname as early as 1960 (Altena 1960). Until now it has never been recorded from French Guiana and this is the first record of the family Thysanophoridae in this territory.
In French Guiana, the species is known from 10 to 500 m a. s. l. both on coastal areas (e. g., Saint-Laurent, Cayenne, Kaw mountain) as well as in the interior in Saül and Trinité.
Two haplotypes were recovered, one from Mana and the other from Saül. Despite their large genetic difference (p - distance 2.7 %), the specimens appear identical in morphology.
description: Published as part of Gargominy, Olivier, Fontaine, Benoît, Tercerie, Sandrine & Zuccon, Dario, 2025, New species and new records of families, genera and species of land snails (Mollusca, Gastropoda) from French Guiana, pp. 155-194 in ZooKeys 1230 on pages 155-194, DOI: 10.3897/zookeys.1230.133585