Anatomical reinvestigation of Archaeopteris macilenta from the Upper Devonian (Frasnian) of South China

Abstract

Archaeopteris macilenta is one of the most widespread plants in the Late Devonian. Based on fossils from the Frasnian Huangjiadeng Formation, Yichang District of Hubei Province, for the first time we study in detail the anatomy of this progymnosperm plant in South China. Ultimate axes are protostelic with three xylem sympodia and lack secondary tissue. Penultimate axes are eustelic, bearing eight sympodia and a thin band of secondary xylem. Radially symmetrical sympodia of mesarch primary xylem produce traces of appendages in a spiral arrangement. Archaeopteris macilenta and A. halliana (A. roemeriana) are dominant in the Frasnian and Famennian, respectively. Comparisons with these two species from other tectonic plates indicate consistent stelar architectures. Global spread, continuous occurrence, and identical anatomy during the Late Devonian indicate that Archaeopteris survived the Frasnian–Famennian extinction event. In this time, endemic genera and cosmopolitan taxa, including Archaeopteris, suggest the palaeogeographic isolation of South China and certain associations with other plates.

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

“…JB, the Jiamusi Block, is considered to be a part of the SXB. Localities of Archaeopteris : 1, Heihe, Heilongjiang, China (Cai, 1981; locality IX in Table 3); 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).…”

A Middle Devonian Callixylon (Archaeopteridales) from Ronquières, Belgium

“…They are currently situated on the Laurussia palaeocontinent. Most Frasnian occurrences of Archaeopteridales are also provided (Meyer-Berthaud et al, 2004, and references therein;Hammond and Berry, 2005;Guo and Wang, 2011) in order to emphasize the spread of those plants during early Late Devonian times. Even though it might be an artifact due to a regional bias in the progymnosperm macrofossil record because of the lack of available localities on Gondwana, the configuration illustrated in Fig.…”