Pertica is a genus of extinct vascular plants of the Early to Middle Devonian (around 420 to 380 million years ago). It has been placed in the "trimerophytes", a strongly paraphyletic group of early members of the lineage leading to modern ferns and seed plants.[4]
Pertica quadrifaria (the type species of the genus) was described in 1972 from compression fossils found in the Trout Valley Formation of northern Maine, USA. It was an upright plant which grew to perhaps as much as a metre (3 ft) in height. It comprised a main, straight stem (axis) with side branches which developed dichotomously, branching many times at increasingly shorter intervals. Some of the terminal branchlets bore masses of erect paired, ellipsoidal sporangia in distinctive tight clusters. The branches were arranged in a spiral pattern, forming four vertical rows. The specific epithet quadrifaria refers to this growth habit.[1][5][6]
Pertica varia was described in 1976 from the Devonian of Eastern Canada. It was considerably taller than P. quadrifaria, reaching a height of nearly 3 m. The sporangia were similar to those of P. quadrifaria, although there were fewer in each cluster.[7]
Pertica dalhousii was described in 1978 from fossils of Early or Middle Devonian age found in New Brunswick, Canada. The plant appears to have been similar to P. quadrifaria (only part is known), comprising a central stem (axis) with spirally arranged dichotomous side branches, some of which terminated in erect clusters of between 32 and 128 sporangia. Further specimens from the same rocks possibly belonged to another species of Pertica, but were not sufficiently well preserved to be named.[2]
Phylogenyedit
The clear differentiation between a main stem (axis) and lateral branches in Pertica, as in other "trimerophytes", has been considered to represent an early stage in the development of a growth pattern that later led to the evolution of megaphylls (large true leaves).[2] Consistent with this, a cladogram published in 2004 by Crane et al. places Pertica in a paraphyleticstem group basal to the seed plants (spermatophytes) which have such leaves.[8]
spermatophytes (seed plants; extant and extinct members)
Other researchers have produced rather different analyses. Rothwell's analysis separates "trimerophytes", like Pertica, from progymnosperms, like Tetraxylopteris, with only the latter being closely related to seed plants.[9]
Referencesedit
^ abcKasper, A.E. & Andrews, H.N. (1972), "Pertica, a New Genus of Devonian Plants from Northern Maine", American Journal of Botany, 59 (9): 897–911, doi:10.2307/2441116, JSTOR 2441116
^ abcDoran, J.B.; Gensel, P.G. & Andrews, H.N. (1978), "New occurrences of trimerophytes from the Devonian of eastern Canada", Botany, 56 (24): 3052–3068, doi:10.1139/b78-369
^Granoff, J.A.; Gensel, P.G. & Andrews, H.N. (1976), "A new species of Pertica from the Devonian of Eastern Canada", Palaeontographica Abteilung B, 155 (5–6): 119–128, cited in Gerrienne, P. (1997), "The fossil plants from the Lower Devonian of Marchin (northern margin of Dinant Synclinorium, Belgium). V. Psilophyton genseliae sp. nov., with hypotheses on the origin of Trimerophytina", Review of Palaeobotany and Palynology, 98 (3–4): 303–324, Bibcode:1997RPaPa..98..303G, doi:10.1016/S0034-6667(97)00010-9
^Taylor, T.N.; Taylor, E.L. & Krings, M. (2009), Paleobotany, The Biology and Evolution of Fossil Plants (2nd ed.), Amsterdam; Boston: Academic Press, ISBN978-0-12-373972-8, pp. 259-261
^Banks, Harlan P. (1980), "The role of Psilophyton in the evolution of vascular plants", Review of Palaeobotany and Palynology, 29: 165–176, Bibcode:1980RPaPa..29..165B, doi:10.1016/0034-6667(80)90056-1
^Crane, P.R.; Herendeen, P. & Friis, E.M. (2004), "Fossils and plant phylogeny", American Journal of Botany, 91 (10): 1683–99, doi:10.3732/ajb.91.10.1683, PMID 21652317
^Rothwell, G.W. (1999), "Fossils and ferns in the resolution of land plant phylogeny", The Botanical Review, 65 (3): 188–218, Bibcode:1999BotRv..65..188R, doi:10.1007/BF02857629, S2CID 40215551
January 01, 1970
pertica, other, uses, disambiguation, genus, extinct, vascular, plants, early, middle, devonian, around, million, years, been, placed, trimerophytes, strongly, paraphyletic, group, early, members, lineage, leading, modern, ferns, seed, plants, temporal, range,. For other uses see Pertica disambiguation Pertica is a genus of extinct vascular plants of the Early to Middle Devonian around 420 to 380 million years ago It has been placed in the trimerophytes a strongly paraphyletic group of early members of the lineage leading to modern ferns and seed plants 4 PerticaTemporal range Early Devonian Middle Devonian PreꞒ Ꞓ O S D C P T J K Pg N Scientific classification Kingdom Plantae Clade Embryophytes Clade Polysporangiophytes Clade Tracheophytes Clade Euphyllophytes Genus PerticaKasper amp H N Andrews 1972 1 Species P dalhousii Doran et al 1978 2 P quadrifaria Kasper amp H N Andrews 1972 1 P varia Granoff et al 1976 3 Description editPertica quadrifaria the type species of the genus was described in 1972 from compression fossils found in the Trout Valley Formation of northern Maine USA It was an upright plant which grew to perhaps as much as a metre 3 ft in height It comprised a main straight stem axis with side branches which developed dichotomously branching many times at increasingly shorter intervals Some of the terminal branchlets bore masses of erect paired ellipsoidal sporangia in distinctive tight clusters The branches were arranged in a spiral pattern forming four vertical rows The specific epithet quadrifaria refers to this growth habit 1 5 6 Pertica varia was described in 1976 from the Devonian of Eastern Canada It was considerably taller than P quadrifaria reaching a height of nearly 3 m The sporangia were similar to those of P quadrifaria although there were fewer in each cluster 7 Pertica dalhousii was described in 1978 from fossils of Early or Middle Devonian age found in New Brunswick Canada The plant appears to have been similar to P quadrifaria only part is known comprising a central stem axis with spirally arranged dichotomous side branches some of which terminated in erect clusters of between 32 and 128 sporangia Further specimens from the same rocks possibly belonged to another species of Pertica but were not sufficiently well preserved to be named 2 Phylogeny editThe clear differentiation between a main stem axis and lateral branches in Pertica as in other trimerophytes has been considered to represent an early stage in the development of a growth pattern that later led to the evolution of megaphylls large true leaves 2 Consistent with this a cladogram published in 2004 by Crane et al places Pertica in a paraphyletic stem group basal to the seed plants spermatophytes which have such leaves 8 euphyllophytes Eophyllophyton basal groups Psilophyton crenulatum Ps dawsonii moniliforms ferns extant and extinct members basal groups Pertica Tetraxylopteris spermatophytes seed plants extant and extinct members Other researchers have produced rather different analyses Rothwell s analysis separates trimerophytes like Pertica from progymnosperms like Tetraxylopteris with only the latter being closely related to seed plants 9 References edit a b c Kasper A E amp Andrews H N 1972 Pertica a New Genus of Devonian Plants from Northern Maine American Journal of Botany 59 9 897 911 doi 10 2307 2441116 JSTOR 2441116 a b c Doran J B Gensel P G amp Andrews H N 1978 New occurrences of trimerophytes from the Devonian of eastern Canada Botany 56 24 3052 3068 doi 10 1139 b78 369 Granoff J A Gensel P G amp Andrews H N 1976 A new species of Pertica from the Devonian of Eastern Canada Palaeontographica Abteilung B 155 5 6 119 128 cited in Gerrienne P 1997 The fossil plants from the Lower Devonian of Marchin northern margin of Dinant Synclinorium Belgium V Psilophyton genseliae sp nov with hypotheses on the origin of Trimerophytina Review of Palaeobotany and Palynology 98 3 4 303 324 Bibcode 1997RPaPa 98 303G doi 10 1016 S0034 6667 97 00010 9 Taylor T N Taylor E L amp Krings M 2009 Paleobotany The Biology and Evolution of Fossil Plants 2nd ed Amsterdam Boston Academic Press ISBN 978 0 12 373972 8 pp 259 261 Banks H P 1975 Reclassification of Psilophyta Taxon 24 4 401 413 doi 10 2307 1219491 JSTOR 1219491 Banks Harlan P 1980 The role of Psilophyton in the evolution of vascular plants Review of Palaeobotany and Palynology 29 165 176 Bibcode 1980RPaPa 29 165B doi 10 1016 0034 6667 80 90056 1 Taylor Taylor amp Krings 2009 p 261 Crane P R Herendeen P amp Friis E M 2004 Fossils and plant phylogeny American Journal of Botany 91 10 1683 99 doi 10 3732 ajb 91 10 1683 PMID 21652317 Rothwell G W 1999 Fossils and ferns in the resolution of land plant phylogeny The Botanical Review 65 3 188 218 Bibcode 1999BotRv 65 188R doi 10 1007 BF02857629 S2CID 40215551 Retrieved from https en wikipedia org w index php title Pertica amp oldid 1214342641, wikipedia, wiki, book, books, library,
