Paleoallium

Last updated

Paleoallium
Temporal range: 50–49  Ma
Ꞓ
O
S
D
C
P
T
J
K
Pg
N
↓
Paleoallium billgenseli SR 10-35-06 holotype.jpg
holotype
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Amaryllidaceae
Genus:† Paleoallium
Pigg, Bryan & DeVore, 2018
Species:
†P. billgenseli
Binomial name
†Paleoallium billgenseli
Pigg, Bryan & DeVore, 2018
Allium cepa bulbils Allium cepa viviparum 002.JPG
Allium cepa bulbils
P. billgenseli bulbil & flowers Paleoallium billgenseli SR 00-05-23 A.jpg
P. billgenseli bulbil & flowers

Paleoallium is an extinct genus of onion-like plant in the family Amaryllidaceae known from the single described species Paleoallium billgenseli. The species is known from Early Eocene sediments exposed in the northeast of the U.S. state of Washington.

Contents

Distribution

Paleoallium billgenseli is described from fossils found in a single location in the Eocene Okanagan Highlands, an outcrop of the Ypresian [1] Klondike Mountain Formation in Republic. [2] The type series of fossils, the holotype, paratypes and additional included fossils were recovered from the UWBM site B4131, which is designated the type locality. Modern work on the fossil-bearing strata of the Formation via radiometrically dating has given an estimated age in the Late Ypresian stage of the early Eocene, between 49.4  ± .5 million years ago at the youngest, [3] with an oldest age estimate of 51.2  ± 0.1 million years ago, given based on detrital zircon isotopic data published in 2021. [4]

An additional attributed fossil from the Allenby Formation around Princeton, British Columbia, was noted to be close to Paleoallium, while a series of fossils from the McAbee outcrop near Cache Creek, British Columbia, were noted as possibly similar but would not be addressed by the paper. [2]

History and classification

The first illustration of a fossil was in the 2011 Fossil plants from Republic: a guidebook published for the Stonerose Interpretive Center where specimen SR 08-36-03 was figured as an "additional flower". The Allenby Formation specimen noted as similar to Paleoallium was figured as an "Unknown structure" by Dilhoff et al (2013). A series of the fossils were formally studied by paleobotanists Kathleen Pigg, Finley Bryan, and Melanie DeVore who published their formal description of the genus and species in a 2018 International Journal of Plant Sciences paper. [2] Pigg, Bryan, DeVore designated the holotype as specimen SR 10-35-06, which was in the paleobotanical collections of the Stonerose Interpretive Center in Republic at that time. An additional paratype series of 15 fossils, also from the Stonerose collections, was designated, and one additional fossil, SR 13-004-010 A&B was discussed and figured, but not included in the type series. The genus name Paleoallium was created as a combination of " Allium ", the modern garlic & onion genus, plus the prefix paleo-. They noted "Allium" is a reference to the remarkable similarity between the fossils and modern onions, but they specified there is no direct implied relationship between any living species discussed in the paper. [2] The species name billgenseli as a patronym honoring William Gensel, Durham, North Carolina botanist who first pointed to the similarity between alliums and the fossils and for his larger contributions to plant sciences. [2]

Since being described, Paleoallium billgenseli has been used a number of times as a molecular dating calibration point for the origins and divergence of Amaryllidaceae. The genus is noted for being the first Amaryllidaceae from the fossil record. [5] [6] [7] [8]

Description

Paleoallium billgenseli spathes are between 3–8 mm (1⁄8–3⁄8 in) wide and 5–12 mm (1⁄4–1⁄2 in) long, granting an obovate to elliptically ovate outline. They range from sprouting flat from the scape to sprouting at a right angle to the spathe length. On well preserved specimens, the surfaces show parallel striations running from base to apex. Two sets of reproductive structures have been identified at the spathe apices-flowers and bulbils. The flowers are usually born in groups of two to six grouped in a helical arrangement near the spathe apex. Each bell shaped flower is born on a small pedicel typically between 2–8 mm (1⁄8–3⁄8 in) long. The bell is composed of three to four lobes and is 3–6 mm (1⁄8–1⁄4 in) wide by 4–8 mm (1⁄8–3⁄8 in) long. Careful preparation of several flowers did not find any fruits, seeds, pollen or anthers, suggesting the possibility the flowers were sterile. Some specimens have distinctly elongated pedicels and either small aborted flowers or buds. The bulbils are sessile around the apex of the scape, in confirmed groups of one to three. There is the possibility that higher numbers may have been borne, but if so, the Authors noted they may have been lost during specimen preparation or obscured under layers of matrix rock. The known bulbils range up to 1 mm × 0.2 mm (3⁄64 in × 1⁄64 in) in size. [2]

Of the known specimens, the scapes are elongate and narrow, ranging between 18–40 mm (3⁄4–1+5⁄8 in) long by 0.8–1.2 mm (1⁄32–3⁄64 in) wide. All specimens have a torn scape base and none are attached to a bulb. They have longitudinal striations as is seen in some onion species and occasionally the apical area will have wisps of tissues around the spathe base, suggested to be outer "onion skin" layers. [2]

Paleoecology

Pigg et al postulated that production of both sexually reproductive flowers and asexually reproductive bulbils to have been a response to environmental factors in the Okanagan Highlands of the Ypresian. The region would have been subjected to volcanism, rapid geographic uplift and rapid ground or surface changes as a result of the activity. These events may have created fluctuating periods of low pollinator activity and high activity. The ability to alternate between sexual and asexual reproduction as conditions warranted would allow plants to take advantage of pollinator availability or conditions such as flood facilitated propagation. [2]

Paleoenvironment

Formations in the Okanagan Highlands represent upland lake systems which were surrounded by a warm temperate ecosystem [2] with nearby volcanism [9] dating from during and just after the early Eocene climatic optimum. The highlands likely had a mesic upper microthermal to lower mesothermal climate, in which winter temperatures rarely dropped low enough for snow, and which were seasonably equitable. [10] The paleoforest surrounding the lakes have been described as precursors to the modern temperate broadleaf and mixed forests of Eastern North America and Eastern Asia. Based on the fossil biotas the lakes were higher and cooler then the coeval coastal forests preserved in the Puget Group and Chuckanut Formation of Western Washington, which are described as lowland tropical forest ecosystems. Estimates of the paleoelevation range between 0.7–1.2 km (0.43–0.75 mi) higher than the coastal forests. This is consistent with the paleoelevation estimates for the lake systems, which range between 1.1–2.9 km (1,100–2,900 m), which is similar to the modern elevation 0.8 km (0.50 mi), but higher. [10]

Estimates of the mean annual temperature have been derived from climate leaf analysis multivariate program (CLAMP) analysis and leaf margin analysis (LMA) of both the Princeton and Republic paleofloras. The CLAMP results after multiple linear regressions for Republic gave a mean annual temperature of approximately 8.0 °C (46.4 °F), while the LMA gave 9.2 ± 2.0 °C (48.6 ± 3.6 °F). Princeton's multiple linear regression CLAMP results gave a slightly lower 5.1 °C (41.2 °F), and the LMA returned a mean annual temperature of 5.1 ± 2.2 °C (41.2 ± 4.0 °F). This is 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 Princeton suggest mean annual precipitation amounts of 115 ± 39 cm (45 ± 15 in) and 114 ± 42 cm (45 ± 17 in) respectively. [10]

Related Research Articles

<i>Tilia johnsoni</i> Extinct species of flowering plant

Tilia johnsoni is an extinct species of flowering plant in the family Malvaceae that, as a member of the genus Tilia, is related to modern lindens. The species is known from fossil leaves found in the early Eocene deposits of northern Washington state, United States and a similar aged formation in British Columbia, Canada.

Trochodendron drachukii is an extinct species of flowering plants in the family Trochodendraceae known from a fossil fruiting structure found in the early Ypresian age Eocene fossils found in British Columbia, Canada. T. drachukii is one of the oldest members of the genus Trochodendron, which includes the living species T. aralioides, native to Japan, southern Korea and Taiwan and the coeval extinct species T. nastae from Washington state, United States.

<span class="mw-page-title-main">Klondike Mountain Formation</span> Geological formation in Washington, United States

The Klondike Mountain Formation is an Early Eocene (Ypresian) geological formation located in the northeast central area of Washington state. The formation is composed of volcanic rocks in the upper unit and volcanic plus lacustrine (lakebed) sedimentation in the lower unit. the formation is named for the type location designated in 1962, Klondike Mountain northeast of Republic, Washington. The formation is a lagerstätte with exceptionally well-preserved plant and insect fossils has been found, along with fossil epithermal hot springs.

<i>Rhus garwellii</i> Extinct species of flowering plant

Rhus garwellii is an extinct species of flowering plant in the sumac family Anacardiaceae. The species is known from fossil leaves found in the early Eocene deposits of northern Washington State, United States. The species was first described from fossil leaves found in the Klondike Mountain Formation. R. garwellii likely hybridized with the other Klondike Mountain formation sumac species R. boothillensis, R. malloryi, and R. republicensis.

<i>Pentacentron</i> Extinct genus of Trochodendralean plant

Pentacentron is an extinct genus of flowering plant in the family Trochodendraceae, consisting of the single species Pentacentron sternhartae. The genus is known from fossil fruits found in the early Eocene deposits of northern Washington state, United States. P. sternhartae are possibly the fruits belonging to the extinct trochodendraceous leaves Tetracentron hopkinsii.

<i>Hiodon woodruffi</i> Extinct species of fish

Hiodon woodruffi is an extinct species of bony fish in the mooneye family, Hiodontidae. The species is known from fossils found in the early Eocene deposits of northern Washington state in the United States and late Eocene deposits in northwestern Montana. The species was first described as Eohiodon woodruffi. H. woodruffi is one of two Eocene Okanagan Highlands mooneye species, and one of five fish identified in the Klondike Mountain Formation.

<i>Barghoornia</i> Extinct species of flowering plants

Barghoornia is an extinct genus of flowering plants in the family Burseraceae containing the solitary species Barghoornia oblongifolia. The species is known from fossil leaves found in the early Eocene deposits of northern Washington state, United States.

<i>Carpinus perryae</i> Extinct species of hornbeam

Carpinus perryae is an extinct species of hornbeam known from fossil fruits found in the Klondike Mountain Formation deposits of northern Washington state, dated to the early Eocene Ypresian stage. Based on described features, C. perryae is the oldest definite species in the genus Carpinus.

Klondikia is an extinct hymenopteran genus in the ant family Formicidae with a single described species Klondikia whiteae. The species is solely known from the Early Eocene sediments exposed in northeast Washington state, United States. The genus is currently not placed into any ant subfamily, being treated as incertae sedis.

<i>Equisetum similkamense</i> Extinct species of fern in the family Equisetacae

Equisetum similkamense is an extinct horsetail species in the family Equisetaceae described from a group of whole plant fossils including rhizomes, stems, and leaves. The species is known from Ypresian sediments exposed in British Columbia, Canada. It is one of several extinct species placed in the living genus Equisetum.

<i>Pteronepelys</i> Fossil genus of plants

Pteronepelys, sometimes known as the winged stranger, is an extinct genus of flowering plant of uncertain affinities, which contains the one species, Pteronepelys wehrii. It is known from isolated fossil seeds found in middle Eocene sediments exposed in north central Oregon and Ypresian-age fossils found in Washington, US.

<i>Fagus langevinii</i> Fossil species of beech tree

Fagus langevinii is an extinct species of beech in the family Fagaceae. The species is known from fossil fruits, nuts, pollen, and leaves found in the early Eocene deposits of South central British Columbia, and northern Washington state, United States.

Paleoserenomyces is an extinct monotypic genus of pleosporale fungus of uncertain family placement. When described it contained the single species Paleoserenomyces allenbyensis. The genus is solely known from the Early Eocene, Ypresian aged, Princeton Chert deposit of the Allenby Formation. Palaeoserenomyces is one of only three described fossil fungus species found in the Princeton Chert, being a tar spot like parasite of the fossil palm Uhlia allenbyensis, and is host for the hyperparasite Cryptodidymosphaerites princetonensis.

Cryptodidymosphaerites is an extinct monotypic genus of pleosporale fungus of uncertain family placement. When described it contained the single species Cryptodidymosphaerites princetonensis. The genus is solely known from the Early Eocene, Ypresian aged, Princeton Chert deposit of the Allenby Formation. Cryptodidymosphaerites is one of only three described fossil fungus species found in the Princeton Chert, and is a hyperparasite of Palaeoserenomyces allenbyensis, itself a tar spot-like parasite of the fossil palm Uhlia.

Eoseira is an extinct genus of diatoms belonging to the family Aulacoseiraceae and containing the single species Eoseira wilsonii. The species is dated to the Early Eocene Ypresian stage and has only been found at the type locality in east central British Columbia.

<i>Dennstaedtia christophelii</i> Fossil species of fern

Dennstaedtia christophelii is an extinct species of fern in the family Dennstaedtiaceae related to the modern hayscented ferns. The species is known from fossil fronds found in early Eocene sites of northern Washington state, United States, and central British Columbia, Canada. The species is suggested to be closest to a Neotropical "Patania" clade and specifically the species Dennstaedtia producta and Dennstaedtia mathewsii.

<i>Okanagrion</i> Extinct genus of damselflies

Okanagrion is an extinct odonate genus in the damselfly-like family Dysagrionidae. The genus was first described in 2021 with a series of eight species included from early Eocene Okanagan Highlands sites in western North America. The genus is known from the Late Ypresian sediments exposed in northeast central Washington at Republic where five species are present, and from the coeval McAbee Fossil Beds near Cache Creek in Central British Columbia, where four species are present. The species richness is attributed to high latitude high alpha diversity resulting from climatic equitability during the Early Eocene in combination with resultant beta diversity between sites due to impassible topographical barriers.

<i>Republica weatbrooki</i> Genus of damselflies

Republica is an extinct zygopteran genus in the damselfly family Euphaeidae with a single described species, Republica weatbrooki. The species is solely known from the Early Eocene sediments exposed in the northeast of the U.S. state of Washington.

Hymenophyllum axsmithii is an extinct species of fern in the family Hymenophyllaceae related to the modern hayscented ferns. The species is known from fossil fronds found in early Eocene sites of northern Washington state, United States, and central British Columbia, Canada. The species is included in Hymenophyllum subgenus Sphaerocionium, with a suggestion to be closest to a group of tropical species in the subgenus that are all specialized as sheltered epiphytes.

<i>Antiquiala</i> Genus of dragonflies

Antiquiala is an extinct anisopteran genus in the dragonfly family Aeshnidae with a single described species, Antiquiala snyderae. The species is solely known from the Early Eocene sediments exposed in the northeast of the U.S. state of Washington. The single fossil known was found at the "Boot Hill" site in Republic and added to the Stonerose Interpretive Center research collection before being officially described in 2019. The genus is thought to be most similar to another early Eocene genus, Huncoaeshna, which was recovered from the Laguna del Hunco Formation in South America.

References

  1. ↑ Moss, P.; Greenwood, D.; Archibald, S. (2005). "Regional and local vegetation community dynamics of the Eocene Okanagan Highlands (British Columbia – Washington State) from palynology". Canadian Journal of Earth Sciences. 42 (2): 187–204. Bibcode:2005CaJES..42..187M. doi:10.1139/E04-095.
  2. 1 2 3 4 5 6 7 8 9 Kathleen B. Pigg; Finley A. Bryan; Melanie L. DeVore (2018). "Paleoallium billgenseli gen. et sp. nov.: fossil monocot remains from the latest Early Eocene Republic Flora, northeastern Washington State, USA". International Journal of Plant Sciences. 179 (6): 477–486. doi:10.1086/697898. S2CID   91055581.
  3. ↑ Makarkin, V.; Archibald, S.B. (2014). "An unusual new fossil genus probably belonging to the Psychopsidae (Neuroptera) from the Eocene Okanagan Highlands, western North America". Zootaxa. 3838 (3): 385–391. CiteSeerX   10.1.1.692.1185 . doi:10.11646/zootaxa.3838.3.8. PMID   25081783.
  4. ↑ Rubino, E.; Leier, A.; Cassel, E.; Archibald, S.; Foster-Baril, Z.; Barbeau, D. Jr (2021). "Detrital zircon UPb ages and Hf-isotopes from Eocene intermontane basin deposits of the southern Canadian Cordillera". Sedimentary Geology. 422. Bibcode:2021SedG..42205969R. doi: 10.1016/j.sedgeo.2021.105969 . S2CID   237717862.
  5. ↑ Xie, D.F.; Tan, J.B.; Yu, Y.; Gui, L.J.; Su, D.M.; Zhou, S.D.; He, X.J. (2020). "Insights into phylogeny, age and evolution of Allium (Amaryllidaceae) based on the whole plastome sequences". Annals of Botany. 125 (7): 1039–1055. doi:10.1093/aob/mcaa024. PMC   7262478 . PMID   32239179.
  6. ↑ Han, T.S.; Zheng, Q.J.; Onstein, R.E.; Rojas-Andrés, B.M.; Hauenschild, F.; Muellner-Riehl, A.N.; Xing, Y.W. (2020). "Polyploidy promotes species diversification of Allium through ecological shifts". New Phytologist. 225 (1): 571–583. doi:10.1111/nph.16098. hdl: 10366/154734 . PMID   31394010.
  7. ↑ Namgung, J.; Do, H.D.K.; Kim, C.; Choi, H.J.; Kim, J.H. (2021). "Complete chloroplast genomes shed light on phylogenetic relationships, divergence time, and biogeography of Allioideae (Amaryllidaceae)". Scientific Reports. 11 (1): 3262. Bibcode:2021NatSR..11.3262N. doi:10.1038/s41598-021-82692-5. PMC   7865063 . PMID   33547390.
  8. ↑ Howard, C.C.; Cellinese, N. (2020). "Tunicate bulb size variation in monocots explained by temperature and phenology". Ecology and Evolution. 10 (5): 2299–2309. Bibcode:2020EcoEv..10.2299H. doi:10.1002/ece3.5996. PMC   7069286 . PMID   32184982.
  9. ↑ 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.
  10. 1 2 3 Greenwood, D.R.; Archibald, S.B.; Mathewes, R.W; Moss, P.T. (2005). "Fossil biotas from the Okanagan Highlands, southern British Columbia and northeastern Washington State: climates and ecosystems across an Eocene landscape". Canadian Journal of Earth Sciences. 42 (2): 167–185. Bibcode:2005CaJES..42..167G. doi:10.1139/e04-100.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.