Dennstaedtia christophelii
Dennstaedtia christophelii | |
---|---|
Holotype fossil | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Division: | Polypodiophyta |
Class: | Polypodiopsida |
Order: | Polypodiales |
Family: | Dennstaedtiaceae |
Genus: | Dennstaedtia |
Species: | †D. christophelii
|
Binomial name | |
†Dennstaedtia christophelii Pigg et al.
|
Dennstaedtia christophelii is an
Distribution
Dennstaedtia christophelii fossils have been recovered from the two sites in the Eocene Okanagan Highlands of Central British Columbia and northeast central Washington state. Two of the described specimens are from the Klondike Mountain Formation in Northern Ferry County, Washington, but recovered from separate outcrops, the "Boot Hill" site B4131 in Republic, and "S100" just to the Northwest of Republic. The third known specimen is from the Tranquille Formation's Falkland site on Estekwalan Mountain in the Columbia–Shuswap region of South Central British Columbia.[1]
History and classification
Fern fossils of the subclass
The group placed the new species into the modern genus
The age of D. christophelii fossils has been used in several
Description
Dennstaedtia christophelii is known only from leaf frond fossils, and as such the rhizomes frond anatomy, and spore morphology is unknown. The known fronds are all incomplete and range from 4.5–6.8 cm (1.8–2.7 in) in lengths, with the overall largest frond length unknown. The fronds have pinnation that grades from having leaflets fully divided at the base to fused leaflets approaching's the frond apices.[1] The individual pinnae are widely spaced along the rachis and range between 5–9 mm (0.20–0.35 in) by 3–5 mm (0.12–0.20 in) wide and progress from subopposite placement basally to alternate nearer the frond apex. They have a petiole which connects from rachis to the squared off base formed by the basal most pinnule pair of the lancolate pinnae. Due to preservation, the lack of any induments along the pinnae is probable, but not conclusively determinable.[1]
There are between 3 and 10 pinnules, 4-5 of which are separate basally, while the apical pinnules are fused. Each of the pinnules are oblong in outline with basal margins that are sessile along the petioles. The margins of each vary from shallowly
Paleoecology
Dennstaedtia christophelii is likely to have been an understory plant in the angiosperm dominated forests surrounding the lake systems.[1]
Paleoenvironment
Both Okanagan Highlands formations represent upland lake systems that were surrounded by a warm temperate ecosystem
Estimates of the mean annual temperature have been derived from climate leaf analysis multivariate program (CLAMP) analysis of the Republic paleoflora, and leaf margin analysis (LMA) of both paleofloras. The CLAMP results after multiple linear regressions for Republic gave a mean annual temperature of approximately 8.0 °C (46.4 °F), with the LMA giving 9.2 ± 2.0 °C (48.6 ± 3.6 °F).[7] LMA results from Falkland returned the higher 10.0 ± 2.2 °C (50.0 ± 4.0 °F), slightly higher than seen at Republic, and CLAMP analysis gave an overall mean annual temperature of 12.8 ± 1.2 °C (55.0 ± 2.2 °F). A bioclimatic-based estimate based on modern relatives of the taxa found at each site suggested mean annual temperatures around 13.5 ± 2.2 °C (56.3 ± 4.0 °F) for Republic and 14.7 ± 2.1 °C (58.5 ± 3.8 °F) for Falkland.[7] These are lower than the mean annual temperature estimates given for the coastal Puget Group, which is estimated to have been between 15–18.6 °C (59.0–65.5 °F). The bioclimatic analysis for Republic and Falkland suggest mean annual precipitation amounts of 115 ± 39 cm (45 ± 15 in) and 105 ± 48 cm (41 ± 19 in) respectively.[7]
References
- ^ S2CID 239036762.
- ^ "Dennstaedtia producta Mett". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2 December 2023.
- ^ "Dennstaedtia mathewsii C.Chr". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2 December 2023.
- PMC 9628275.
- .
- ^ Archibald, S.; Greenwood, D.; Smith, R.; Mathewes, R.; Basinger, J. (2011). "Great Canadian Lagerstätten 1. Early Eocene Lagerstätten of the Okanagan Highlands (British Columbia and Washington State)". Geoscience Canada. 38 (4): 155–164.
- ^ doi:10.1139/e04-100.