A Taxodiaceous Seed Cone from the Triassic of Antarctica

Abstract

A silicified seed cone is described from the lower Middle Triassic of A silicified seed cone is described from the lower Middle Triassic of Antarctica. The cone measures up to 3.4 cm long and 1.4 cm wide, and consists of helically arranged cone scales attached to a eustelic axis. Bract and ovuliferous scale are approximately of equal length and fused at the base. The bract is entire and vascularized by a single trace. The ovuliferous scale contains five distal lobes, each vascularized by a terete strand that divides to form a smaller trace to each of the five inverted ovules. Ovules are small and flattened with the three-parted integument attenuated into oppositely positioned lateral wings. The Triassic specimens are compared with both extant and fossil conifer seed cones and believed to have their closest affinities within the Taxodiaceae.

Evolution and Relationships of the Conifer Seed Cone Telemachus: Evidence from the Triassic of Antarctica

“…Telemachus Anderson emend. Yao, Taylor et Taylor, 1993 Diagnosis (emended). Seed cone with OCs helically arranged on a thick woody axis; each OC composed of a bract and ovuliferous scale fused for about half their length; bract simple.…”

“…The genus was subsequently discovered in a number of localities throughout Gondwana, including the Middle Triassic of New Zealand (Retallack 1981), Antarctica (Yao et al 1993;Axsmith et al 1995Axsmith et al , 1998, Argentina (Morel 1994;Lutz 2006), and Chile (Nielsen 2005). As a result of these reports, Telemachus represents the most widely distributed conifer seed cone from the Triassic of Gondwana.…”

“…The systematic affinities of Telemachus and the relationship of the fossil with both living and extinct families of conifers also remain unclear. The genus has been variously assigned to the extinct conifer families Voltziaceae (Retallack 1981;Yao et al 1993) and Cycadocarpidiaceae (Anderson and Anderson 1983) on the basis of seed cone features. Telemachus has also been related to Podocarpaceae because of its frequent association with multiveined leaves that exhibit podocarpaceous features (see Axsmith et al 1998).…”

“…Telemachus has also been related to Podocarpaceae because of its frequent association with multiveined leaves that exhibit podocarpaceous features (see Axsmith et al 1998). The presence of Telemachus in Triassic shales from Antarctica was first reported by Yao et al (1993), on the basis of two specimens of the type species, Telemachus elongatus, collected on Mount Falla, from the Upper Triassic Falla Formation in the Central Transantarctic Mountains (CTM). Subsequently, more than 50 additional specimens were collected from two different localities: a site informally known as Alfie's Elbow, also in the CTM, and the Allan Hills, in southern Victoria Land.…”

“…Parasciadopitys Yao, Taylor et Taylor (1997), from the Middle Triassic of Fremouw Peak, CTM, was described from permineralized specimens with multiovulate ovuliferous complexes (OCs) and was tentatively assigned to the Taxodiaceae (¼Cupressaceae sensu lato). The relationship between Parasciadopitys and Telemachus was briefly discussed by Yao et al (1997), on the basis of features observed in both seed cones, despite the fact that the specimens represented different preservational modes. Here we apply a modification of the classic transfer technique (Escapa et al 2010) in order to understand the three-dimensional morphology and anatomy of Telemachus and to compare this cone with Parascia-dopitys.…”