Melvillipteris quadriseriatagen. et sp. nov., a new plant assigned to Rhacophytales from the Upper Devonian (Famennian) of Arctic Canada

Abstract

A new plant of Late Devonian (Famennian) age, Melvillipteris quadriseriata gen. et sp. nov., is reported from Melville Island, Nunavut, Canadian Arctic Archipelago. Main axes and two orders of lateral branches are recognized. The main axes are monopodial in habit, with a zigzag and/or upright appearance and dense adventitious roots attached on some internodes. First-order branches are inserted on the main axes in distichous pairs, showing a quadriseriate pattern (i.e. alternate pairs); they bear one or two sterile ultimate appendages on the proximal portions, and then distally bear alternate second-order branches. Second-order branches bear alternate ultimate appendages which may be fertile or sterile; the sterile ultimate appendages are composed of one or two successive dichotomies, terminating in oppositely recurved tips, and fertile appendages show an elaborate branching system. Each fertile appendage has an initial dichotomy forming two sister branches, each of which further divides three or four times to produce ultimate divisions terminated by sporangia. Two to four small fusiform sporangia are grouped in a truss which is supplied by penultimate division of the fertile appendage. The sporangia have a pointed tip and a longitudinal dehiscence. This new plant resembles other plants with a quadriseriate branching pattern (e.g. Rhacophyton Crépin, Cephalopteris Nathorst, Protocephalopteris Ananiev, Ellesmeris Hill, Scheckler & Basinger and Protopteridophyton Li & Hsü), and is assigned to the Rhacophytales. Its similarity to and divergence from the rhacophytaleans, cladoxylopsids and other related plants are discussed.

A new Late Devonian flora from Sonid Zuoqi, Inner Mongolia, northeastern China

“…Remarks.-Our material is assigned to the genus Melvillipteris as a new species, M. sonidia n. sp. This genus was established from the Late Devonian (Famennian) of Arctic Canada (Xue and Basinger, 2016). The similarities between M. sonidia n. sp.…”

“…Their comparisons remain valid and applicable to M. sonidia n. sp. Besides Melvillipteris, many other plant genera (e.g., Rhacophyton Crépin; Cephalopteris Nathorst; Protocephalopteris Ananiev; Ellesmeris Hill, Scheckler, and Basinger; Chlidanophyton Gensel; Eocladoxylon Koidzumi; Protopteridophyton Li and Hsü) were collectively included in the Rhacophytales (Hilton, 1999;Berry and Wang, 2006;Taylor et al, 2009), and the quadriseriate branching in these taxa may be a shared derived character (synapomorphy) (Xue and Basinger, 2016). However, taxonomic assignment of Melvillipteris to the Rhacophytales remains uncertain and requires further phylogenetic analyses.…”

“…Melvillipteris quadriseriata Xue and Basinger, 2016, by original designation, from the Parry Islands Formation (Famennian), Upper Devonian, eastern Melville Island, Canadian Arctic Archipelago.…”

“…Localities of Archaeopteris: 1, Heihe, Heilongjiang, China(Cai, 1981; locality IX in Table3); 2, Sonid Zuoqi, Inner Mongolia, China (flag, this study); 3, Southeastern Altay, Russia(Gutak et al, 2011); 4, North Timan, Russia(Orlova et al, 2016); 5, Bear Island, Norway(Nathorst, 1902;Edwards and Berry, 1991); 6, Namur, Belgium (Fairon-Demaret and Leponce, 2001); 7, Kiltorcan Hill, Ireland(Dawson, 1871); 8, Ellesmere Island, Canada(Andrews et al, 1965); 9, New York, USA(Carluccio et al, 1966); 10, Pennsylvania, USA(Beck, 1971); 11, West Virginia, USA(Phillips et al, 1972); 12, Eastern Cordillera, Colombia(Berry et al, 2000); 13, Sierra de Perijá, Venezuela(Berry et al, 2000); 14, Eastern Anti-Atlas, Morocco(Meyer-Berthaud et al, 1999); 15, Eastern Cape, South Africa(Anderson et al, 1995); 16, Nanjing, Jiangsu, China(Wu et al, 1982); 17, Changyang, Hubei, China(Hao and Mei, 1987;Guo and Wang, 2011); 18, Chizhou, Anhui, China(Guo and Wang, 2009); 19, Xinhui, Guangdong, China(Cai et al, 1987); 20, New South Wales, Australia(Young, 2007;Meyer-Berthaud et al, 2016a). Localities of Melvillipteris: 2 (this study) and Melville Island, Canadian Arctic Archipelago(Xue and Basinger, 2016).…”

“…Morphological comparisons between Melvillipteris quadriseriata and M. sonidia n. sp. Data for M. quadriseriata based onXue and Basinger (2016). All measurements are in mm.…”