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Fossil (化石)






Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily

[ Triassic/Rhaetic, Jurrasic, Carboniferous/Permian, Precambrian ]

fossil formation
索引
Fig. Diagram showing the process of fossilization. Fossilization requires embedding in sediment. Contitions of preservation: impressiosn, core, true petrification, and natural cast. Note autochtonous (primary) and allochtonous (secondary) deposits. Synchronous allochtony by transport before fossilzation, and heterochronous allochthony by transport after fossilization.

Evolution of algae (藻類の進化)


Diatoms
diatom
Fig. 4. Stratigraphic changes in valve morphology of Stephanodiscus species, which occurred monospecifically. From left to right; valve diameter, open squares (minimum), solid small circles (average) and solid squares (maximum); distribution of initial valve diameter; frequency of vestibule, pore or short tube for mantle strutted process external opening, vestibule in dashed line, pore in dotted line and tube in solid line; spine-bearing valve ratio, broken line showing the exceptionally high values intercalated by S. vestibulis's occurrence; distribution of fascicle/valve diameter ratio called fascicle density in this study; schematic diagram showing biostratigraphic ranges and phylogenic hypothesis for Stephanodiscus cf. vestibulis, S. umbilicatus, S. praesuzukii and S. suzukii in Lake Biwa with reference to S. vestibulis. (Saito-Kato et al. 2015)
Green algae

algae
Fig. (a-e) Calcareous green algae. (a) Oligoporella, (b) Petrascula, (c) Eugonophyllum, (d) Halimeda, (e) Boueina. l.s. and t.s. = longitudinal and transverse sections. (f-n) Green algae. (f) Tasmanites, (g) Calcisphaera, left = non-radiosphaerid, right = radiosphaerid, (h) Eovolvox, left, as preserved in CaCO3, right, reconstruction with inner daughter colony, (i) Botryococcus, left = colony, right = sections through tallus, (j) Recent Closterium (above), with zygospore, (below), (k) fossil Closterium-like desmid (scale unknown), (l) endolithic chaetophoralean-like alga, (m) Pediastrum, (n) recent Cosmarium with zygospore to right.
algae
Fig. a-c: Charophytes. a: Chara plant, b: Detail of stem, branches, oogonia and antheridia, c: Stellatochara progonite (bar = 100 μm). d-g: Calcareous red algae. d: Solenopora, e: Lithothamnion, f: Corallina, d: Epiphyton.

Alteration of generation
All vascular plants: haploid generation = gametophyte, diploid generation = sporophyte
- life cycle = biphassic system
Life cycle of Ulva: G = Sp. → primitive
Most plant species: G << Sp

ultrastructure: antrophic, heterotrophic
Gametophyte = n → reduced division (≠ meiosis) → Gamete (antheridium = sperm, oogonium = egg)

Angiosperm: antrophic gametophytes, which have no chloroplasts, do not exist

Mesozoic

Mesozoic (中生代)


(*: fossil record = extinct)

Seed plants in mesozoic

Division Spermatophyta 種子植物門

Subdivision Gymnospermae 裸子植物亜門

Class Cycadopsida ソテツ綱
Subclass Pteridospermidae* シダ状種子植物亜綱
Devonian - Jurassic (fossil record)
integument (珠皮) formed by telome
  1. formed by symphysis (癒合)
  2. synangium (合生胞子嚢)
Order Pteridospermales シダ状裸子植物目
= Cycadofilicales ソテツシダ目 (seed ferns): sometimes not established

Pteridospermae
Fig. Pteridospermae. A-D: Lyginopteris oldhami (reconstructed by piecing leaves based on the characteristics leaf surface). A: Sphenopteris hoeninghausi (stem) + B + C (ovule): Lagenostoma + D, E: Aulacothea microsporophyll (小胞子葉). F: Whittleseya elegans microsporophyll (or pollen sac). G: Lagenostoma sinchlairi microphyll attached with seeds. H: cross-section of Stephanospermum akenioides seed.
A: close to fern, B: close to seed plant, D: pollen?
→ can be regarded as seeds attached with fern leaves

Lyginopteridaceae*: Devonian - Carboniferous

considered to be the most primitive seed plant reported from fossils
Lyginopteris Potonié: lower Carboniferous (gymnosperms appeared at the latest)- upper Carboniferous (leaf = Sphenopteris)

Medullosaceae*: Carboniferous - Permian

Medullosa Cotta: upper Carboniferous - Permian
vascular bundle = polystele
Medullosa
Fig. Vascular systems of Medullosaceae

Cycadofilicales
Fig. Medullosa (Cycadofilicales)
fossil from the late Carboniferous
(reconstructed by Andrews)

Calamopityaceae*: Devonian - Carboniferous

Calamopitys Unger: fissil of stem

Peltaspermaceae*: Permian - Triassic

Lepidopteris Schimp.: fossil of leaf
Peltaspermum Brongn.: fossil of female reproductive organ

Corystospermaceae: Triassic

Pterorachis Freng.; fossil of male reproductive organ

Caytoniaceae: Triassic -Cretaceous

Caytonia Thomas: fossil of female reproductive organ

Order Caytoniaceae = Corystospermaceae + Caytoniaceae (when established)
Glossopteridaceae: Carboniferous - Permian → distributed mainly in Gondwana land (Order Glossopteridales, when established)

Gangamopteris McCoy: leaf fossil
Glossopteris Brongn.: leaf fossil

Subclass Cycadidae ソテツ亜綱
Order Bennettiales*: Triassic- end of Mesozoic)

Cycas
Fig. Bennettiales. A: Williamsonia sewararana resonstruction. B: Williamsoniella coronata, sporophyll with micro- and macro-sporophyll. C-G: Cycadeoidea. C: C. marshiana reconstruction. D: C. gibsoniana

Willamsoniaceae*

Williamsonia Carr. (Bennetiocarpus: seed fossil, Bennettistemon: male inflorescence fossil)

Wielandiellaceae*

Wielandiella Nathorst (= Anomozamites Schimper)
Williamsoniella Thomas (= Nilssoniopteris Nathorst)

Cycadeoideaceae

Cycadeoidea Buckland

Order Cycadales ソテツ目
Nilssoniaceae*: Jurassic - Cretaceous
Subclass Pentoxylidae ペントキシロン亜綱*
Order Pentoxylales*
Class Coniferopsida 球果植物綱
Order Cordaitales
Upper Devonian - Permian, many fossils collected from the Northern Hemisphere
tall tree branching at the upper part, slim stem, large and clear pith
leaf: spiral arrangement, spoon-like, macrophyllous, single leaf ≈ 1 m long
Two plausible evolutionary pathways (similar with Araucariaceae
  1. Lebuchia (Walchia) → PrendonaliaUlmanniaAraucaria
  2. ErastiodendronStachyotaxusPodocarpus

silicified wood
Silicified wood (珪化木)

[Cretaceous]

Cretaceous (白亜紀)


Table. Pre-Aptian (≈ early Cretaceous) angiosperm fossil record → first angyosperms
Age: Megafossil claims (wood, leaf, etc.) ↔ Pollen claims
Barremian: OnoanaClavatipollenites
Hauterivian:
Valanginian: Carpolithus
Barriasian: Tyrma fruits ↔ Tricolpollemites
'Tithonian': ProblematospermumPterocarya, Trifossapollenites
Kimmeridgian: Palmoxylon, UngeriaSporojuglandoidites
Oxfordian: Sahnioxylon, Montsechia
Callovian:
Bathonian: Phyllites, SogdianiaMagnolia-type, Nelumbium-type
Bajocian: Suevioxylon, Caytonia'Clavatipollenites'

Early Jurassic: Propalmophyllum, Gramiane, Sassendorfites, FraxinopsisEuycommiidites, 'Clavatipollenites'

Late Triassic: Furcula, Sanmiguelia ↔ Eucommiidites
Early Carboniferous: ↔ Tetraporina, Triporina

[Jurassic]

Jurassic (ジュラ紀)


Table. Geological distribution of Jurassic plants *: and allied species
                                Triassic Jurassic Cretaceous  Tert.
                                                  Lower Upper

Equisetales
  Equisetes columnalis*                  ========
  Neocalamites                  ======== ========
Filicales
  Marattiopsis                  ======== ======== ===== ?
  Todites                       ======== ========
  Osmundites                             -------- ===== ===== ======
  Cladophlebis denticulata*     ======== ===§=== ===== ?
  Cladophlebis browniana                          =====
  Gleichenites                  ======== ======== =§== ===== ======
  Dictyophyllum laccopteris     ======== ======== ===== ?
  Matonidium                             ======== =====
  Hausmania                              ======== =====
  Rhffordia                              ======== =§==
  Klukia                                 ======== ===== ?
  Eboracia                                    === =§==
  Lacopteris, Nathorstia                          ===== =====
  Tempskya                                              =====
  Sphenopteris (Onichiopsis)                            =====
  Coniopteris hymenophylloides*          ========
Pteridospermae
  Thinnfeldia*                  ======== ======== =====
  Weichselia                                      =====
Cycadophyta
  Cycadeoidea                            ======== §=== ------
  Williamsonia                  ======== ===§=== =====
  Wielandiella                  ======== ========
  Ptieophyllum                           ========
  Otozamites                    ======== ======== =====
  Ctenis                        ======== ========
  Pseudoctenis                           ===§=== =====
  Dictyozamites                          ========
  Nilssonia                     ======== ======== ===== ===== ------
  Ptilophyllum                           ======== =====
  Zamites                                ======== =====
  Zamiophyllum, Pseudocycas                       ===== =====
Ginkgoales
  Ginkgoites                    ======== ======== ===== ===== ======
  Baiera                        ======== ======== =====
  Czekanowskia                  ======== ========
  Phoenicopsis                           ========
  Eretmophyllum                          ========
  Dammarites                                      ===== =====
  Sequoites                     ======== ======== ===== =====
  Mariconia                                             =====
  Widdringtonites                                    == =====
  Athritaxites                      ==== ======== ==
  Pinites                                ======== ===== ===== ======
 Podozamites                            ===§=== ===== =====
Coniferales
  Araucarites (Araucariphyllum) ======== ======== ===== ===== ------
  Pagiophyllum                  ======== ======== ===== ?
  Brachyphyllum                 ======== ===§=== ===== ?
  Pinites, etc.                 ======== ===§=== ===== ?
  Podozamites                       ==== ===§=== ==
  Caytoniales
  Sagenopteris                	  ==== ======== ==

Seed plants in Mesozoic (中生代種子植物)

Pollen (花粉)
pollen
Fig. Time distribution and presumed relationships of principal early Cretaceous and Cenomanian angiosperm pollen types (e-p), and selected pre-Cretaceous pollen types (a-d). a: Eucommiidites, b: Triassic reticulate-columellar monosulcate of Cornet, c: cycad-type alveolar monosulcate, d: saccate alveolar pollen of Caytoniaceae and Corystospermaceae, e: Clavatipollenites, f: Retimonocolpites, g: Stellatopollis, h: Liliacidites, a possible monocot, I: reticulate tricoplate, j: striate tricoplate, k: smooth tricoplate, l: grain with tricolporate tendency, m: tricolpodiorate, n: polyporate, o: smooth, oblate-triangular tricolporate, p: early member of triporate Normapolles complex.
Leaf
Vein (葉脈): veinlet is present - developmental order of veins
pollen
Fig. Principal early Cretaceous and Cenomanian angiosperm leaf types. a: small, pinnately veined leaf of Vakhrameev, b: reniform, c: serrate, d: oblanceolate, e: Ficophyllum, f: Acaciaephyllum, g: lobate reniform, h: peltate, actinodromous, i: ovate cordate, j: pinnatifid Sapinodopsis, k: early plantanoid, l: compound Sapindopsis, m: later plantanoid, with rigidly organized fine venation, n: Liriophyllum, o: dichotomously compound, p: secondarily simple platanoid derivative.

Triassic plants (三畳紀)


Table. Geological distribution of some Triassic and Rhaetic plants

PaleozoicTrias--Rhaetic
BuntKeupRhaeticJurassic
EquisetalesEquisetites======================================>
Schizoneura: Neocalamites====================================
LycopodialesLycopodites======================================>
Lycostrobus: Lepidostrobus===============-----------=======
Pleuromeia=======
FilicalesMarattiopsis============================
Danaeopsis==============
Todites=====================
Cladophlebis nebbensis, etc.___=========================
Gleichenites=======================>
Hausmannia================>
Dictyophyllum___================================
Clathropteris=====================
Laccopteris: Andriania=====================
Asterotheca====================================
Neuropteridium==============
PteridospermaeGlossopteris=============================
Thinnfeldia & allied forms___================================
Lepidopteris==============
Callipteridium======================
CycadophytaWielandiella: Williamsonia==============
Pterophyllum====================================
Nilssonia=======================>
Sphenozamites====================================
Pseudoctenis: Ctenis=====================
Otozamites==============================>
GinkgoalesGinkgoites=======================>
Baiera====================================
Czekanowskia=============================
Rhipidopsis=============================
ConiferalesAraucarites======================================>
Voltzia======================
Stachyotaxus=======
Palissya=======
Podozamites================>
Plantae Incertae SedisRhexoxylon==============
Chiropteris=============================
Pelourdea====================================
CaytonialesSagenopteris=======================>

Animal (動物)


Elephant (ゾウ)
Elephantidae, elephants
horse
Fig. 83. Former and present distribution of Proboscideans: in the Late Tertiary natives of Africa, Eurasia, and North America; in the Pleistocene in South Africa as well. Disjunctive distribution of modern times (Africa: Loxodonta africana; South Asia: Elephas maximus). In the Late Tertiary and Quaternary spreading over the Arabian peninsula, Berign and Panama bridges.

Paleozoic (古生代)


(Wegener 1912)

Diversity of plant distribution (植物分布の多様性)


Gondwana flora (ゴンドワナフローラ)

recorded from glaciers developed in the upper Permian

Glossopteris: leaf = main vein (costa), lateral vein – dichotomous branching
Gangamopteris: leaf = no main vein, cold resistance
Gondwana
Fig. 1, 3: Glossopteris, 1: branch developing leaves. 3: leaf. 2, 4: Gangamopteris, 2: branch developing leaves. 4: leaf

Cathaysia flora (カタイシアフローラ)

Gigantopteris: characteristic distribution after the Permian

Angara or Siberia flora (アンガラフローラ)

Seed fern
Plant
Alethopteris Sternberg
Pennsylvanian, Minto Formation
Rothwell, New Brunswick
Collector: WB Evans
Seed fern
Plant
Alethopteris Sternberg
Pennsylvanian, St. Clair,
Pennsylvania
United States of America
Collector: WH Forbes
Leaves of Calamites
Plant
Annularia Sternberg
Pennsylvanian, Clifton Formation
Clifton, New Brunswick
Collectors: RF Miller and
J McGovern, 1994
Giant horsetail plant
Plant
Calamites Suckow
Pennsylvanian, Tynemouth
Creek Formation
Gardner Creek, New Brunswick
Collector: F Sherwood, 1989
Plant
Plant
Psilophyton charientos Gensel
Devonian, Campbellton Formation
Dalhousie Junction, New Brunswick
Collector: PG Gensel, ca 1986
Plant
Plant
Lepidodendropsis Sternberg
Mississippian, Albert Formation
Bloomfield, New Brunswick
Collector: RF Miller
(St John Museum, Sept 19 2014)

Carboniferous and Permian plants (石炭紀二畳紀)


The floras chronologically differed between the Northern and Southern Hemisphere.

The geological distribution of Carboniferous and Permian plants.

DevonianCarbonPermianTriossic
LowerUpperLowUpper
WestphalianStephanian
Spehnopsida
Asterocalamites===§=======
Calamites===========§======================
Asterophyllites=======================
Annularia=======================
Lobatannularia

=====

=======----------------------->
Schizoneura

=====

=================
Phylletheca

====

=======================================>
Euisetites=======================================>
Sphenophyllum========================================>
Cheirostrobus=======
Lycopsida
Lepidodendron

=====

===========§===================
Lepidopholois

=====

====§====
Sigillaria

====

====§==============
Stigamaria

=====

================================--
Archaeosigillaria

=====

=======
Bothrodendron

=====

====§====
Aselanus========------
Lepidocarpon===============
Miadesmia========
Lycopodites==============================================>
Selaginellites

=====

===============================>
Pteropsida
Coenopterideae
Botryopteris==============================
Metaclepsydropsis========================
Stauropteris=======
Diplolabis===============
Botrychioxylon=======
Etapteris========
Clepsydropsis==============================
Ankyropteris=======
Asterochlaena=======================
Other ferns
Thamnopteris

=====

=======
Psaronius===================§===
Rhacopteris (Anisopteris)===§===
Oligocarpia====§===================
Spermatophyta
Pteridospemales
Pecopteris============§=========================
Cladophlebis===============================>
Alethopteris====§===================
Lonchopteris====§============----------------------------------
Callipteris==============
Odontopteris

====

===========§===
Callipteridium===========§===
Neuropteris

====

====§====
Neuropteridium=====================
Gondowanidium

====

=======
Linopteris====§===================
Adiantites==========§===========--------------------------------------------------->
Sphenopteris=====================================================>
Mariopteris====§======
Sphenopteridium

=====

=======
Rhodea

=====

===§===========
Cardiopteris=======
Gigantopteris

=====

=======
Taeniopteris

======

===§===
Thinnfeldia=======================>
Gangamopteris

=====

=======
Glossopteris

=====

=====================
Chiropteris=======================>
Stems, etc.
Lyginopteris===============
Heterangium=======================
Rhetinangium=======
Megaloxylon========
Calamopitys=======
Stenomyelon=======
Protopitys=======
Cladoxylon

===

=======
Medullosa=======================
Cycadales & Bennettitales
Dioonites=======================>
Pterophyllum

====

===============================>
Sphenozamites=======================>
Ginkgoales
Baiera

====

=======================>
Sanortaea

====

=======
Cordaitales
Cordaites==============================-------------------------->
Pitys: Archaeopitys=======
Coenoxylon

===

=====
Dolerophyllum=======================
Coniferales
Araucarites===§===================
Walchia

====

===============
Ernestia=======
Voltia

===

==============
Pityanthus========
Pityospermum==============
Dicranophyllum

===

===================§==========
Ullmannia

===

=======
Gemphostrobus==========
Plants of uncertan position
Psygmophyllum

===

=================================
Plagiozamites===============
Tingia

====

=======
Pelourdea

====

=====================

Cordaites
Cordaites

Cordaites trees are an extinct group of seed-bearing conifer-like plants. Although an important part of the Pennsylvanian landscape, they only made up ten percent of the forest biomass. Cordaites trees, up to 30 meters tall, grew on the lowlands, while shrub varieties and shorter trees with stilt-like roots lived in swamps along the edges of seashores and estuaries.
Like many fossil plants, different parts of the tree may are known by different names. The former genus “Dadoxylon” refers to fossilized wood and includes logs that likely belonged to cordaites trees. The strap-like leaves, known as Cordaites, vary in size from a few centimeters to one meter in length. The unfertilized seeds, Cardiocarpus, were borne on the leafy branches of the tree and are often found in large numbers.

(St John Museum, Sept 19 2014)

Etapteris
Etapteris lacattei

Origin of terrestrial plants (陸上植物の起源)


Taxonomical classification

Division Rhyniophyta (ライニア門)

= Division Pteridophyta, s.l.

Subdivision Psilophytina (裸茎植物亜門)

Class Rhyniopsida (ライニア綱)
= Class Psilophytopsida (古生マツバラン綱)
1970 Banks: three major groups =

Rhyniales +
Trimerophytales (Trimerophytina) +
Zosterophyllales (Zosterophyllophtina)

Order Rhyniales (ライニア目)
stele = centrarch 心原型 (≈ endarch 内原型)
lacking secondary vascular bundle tissues
sporangium - split vertically
Rhyniaceae (ライニア)
Rhynia Kidst. et Lang, Horneophyton Bargh. et Darrah (= Hornea Kidst. et Lang)
Rhynia
Rhynia: R. major (2n) → same species (?) → (n) R. gwyene-vaughan

Hypothesis: R. gwyene-vaughan: developing inconstant branch (不定枝) → R. major
unbalanced dichotomous branching → differentiation of stems and branches (dichotomous, polyaxial branching)
Selaginella tamariscina (P. Beauv.) Spring and Selaginella remotifolia Spring: planate, dichotomous branching - derivation from crisscross, dichotomous branching

Trimerophytaceae (Order Trimerophytales in opinion)
Dawasonites Halle
Trimerophyton Hopping (トリメロフィトン)

Trimerophyton
three branching → evolving to Equisetum

Cooksoniaceae (クックソニア) (opinion, merged into Rhyniaceae)
Cooksonia Lang
Cooksonia
Asteroxylaceae (アステロキシロン)
Protolepidodendron Krejči (Gr. protos = first, lepidos = scale, dendron = tree)
Protolepidodendron
Fig. 1. Protoledpidoendron scharyanum (Mid-Devonian, Germany. Lower Devonian, Yungnagn, China)

a: branch attached with threadlike foliage, b: magnified branch surface. 2.Lepidodendron oculis-felis (Lower Permian). 3. Calamites cisti (Upper Permian, Germany). 4. Calamites, a: medullary groove (髄孔), b: xylem, c: medullary ray (射出髄). 5. Archaeopteris latifolia. 6. Archaeopteris hibernica. 7. Leaf based of several Lycopods: a, young twig of arborescent Lycopod; b, Lepidodendron; c, Lepidophloios; d, Bothrodendron

Calamophyton: mid-Devonian → morphologically similar with Hyenia = classified into Arthrophyta, homospore or heterospore is unknown
Sphenophyllum (Gr. sphenos = wedge, phyllum = leaf): tree fern (Articulatae, 有節類). strobilus = Bowmanites. homospore
Order Zosterophyllales (ゾステロフィルム目)
lateral sporangia (側生胞子嚢) → sporangium = transverse dehiscence

Zosterophyllales
H-shaped or K-shaped branching
exarch → Lepidophyta

Zosterophyllaceae
Bucheria Dorf, Zosterophyllum Daws.
Zosterophyllales
Fig. A: Horneophyton lignieri. B: Zosterophyllum rhenanum Kräusel u. Weyland. Upper Devonian (reconstruction) (Weyland 1935)

[the present ferns]

[Division Rhyniophytaは上記]

Division Pteridophyta シダ植物門

Subdivision Psilophytina 裸茎植物亜門

Class Psilophytopsida 古生マツバラン綱
phylogenetic relations are unknown (taxonomical group of convenience)
Order Psilophytales (プシロフィトン/古生マツバラン)
Silurian - Permian
Psilophytaceae: Psilophyton Daws.
Fossil records from chert: Rhynia, Psilophyton, Taeniocrada, Cooksonia, Sporogonites

Body plan (structure, 体制)

Subdivision Lepidophytina (小葉植物亜門)

= Microphyllophytina (小葉植物亜門), Lycopodiinae, Lycophytina, Lycopsida
Class Aglossposida (無舌綱)
Order Protolepidodendrales (古生ヒカゲノカズラ)
early Devonian - ending Devonian (partly until Carboniferous)

maostly herbs = secondary growth unproved

Drepanophycaceae: Baragwanathia, Drepanophycus
Protolepidodendraceae: Arachaeosigillaria Kidston, Lepidodendropsis Lutz, Protolepidodendron Krejči
Lycopodiaceae (2 species in existence): after Carboniferous

Fossil species: Lycopodites Brongn, Paurodendron Fry

Class Glossopsida (有舌綱)
Subclass Primofilicidae* (原シダ亜綱)
Order Protopteridales* (古生シダ): Devonian-Carboniferous Protoptericaceae* (古生シダ): Protopteridium, Svalbardia
Order Cladoxylales* (クラドキシロン): mid-Devonian-Carboniferous
only sporophyts reported, erect above-ground stem, dichotomous or irregular branching, crown developed on the top

Fern-like foliage (羊歯的葉)

Taxonomical and phylogenetical positions are not clearly determined
fern-like
Fig. Lower Carboniferous pteridosperm fronds (石炭紀下部シダ状種子植物). A, Sphenopteridium capillare, complete frond. B, Adiantites machanekii, fragment of frond showing form of ultimate segments. C, Sphenopteris affinis, portion of frond. D, Rhodea smithii, ultimate pinna. E, Diplopteridium teilianum, reconstruction of complete frond with Telangium type of pollen-bearing organs attached. F, pinna of Sphenopteris type, from Diplopteridium teilianum.
fern-like
Fig. Upper Carboniferous peridosperm fronds. A, Mariopteris, pinna showing double dichotomy. B, Mariopteris pinnule. C, Sphenopteris pinnule. D, Pecopteris (Asterotheca) daubrei, pinnule. E, Pecopteris armasii, pinnule. F, Odontopteris, complete frond. G, Odontopteris pinnule. H, Alethopteris, apex of frond. I, Aletopteris pinnule. J, Lonchopteris pinnule. K, Neuropteris, apex of frond. L, Neuropteris pinnule. M, Linopteris pinnule.

The evolution of seed plants (種子植物の進化)


Heterospory (異型胞子)

origin of seed: gymnospermae vs angiospermae ⇒ monophyly or polyphyly?
Homosproy and heterospory
Fern → hydro-fern = heterospory
Embryo – leaves keeping spores

macrosporangium → [sporocyst] → megaspore
microspograngium → [sporocyst] → microspore

Precambrian (始生代)


In the 1950's laboratory experiments showed that electrical discharges, like lightning, may have caused chemical compounds on the early earth to combine, forming the building blocks for life. Since then, theories for how life began have explored numerous paths. Early in the earth’s evolution the chemicals necessary for life existed in the oceans or atmosphere, but for hundreds of millions of years the Earth was probably lifeless. If lie had evolved, bombardment by asteroids and comets would have vaporized the oceans, sterilizing the planet. Asteroids and comets likely brought organic compounds with them. Heavy bombardment probably ended 3.8 billion years ago. Rocks about this age contain organic carbon, suggesting life arose quickly.
Rocks 3.5 billion years old contain the first fossils of simple (prokaryotic) cells that lack a nucleus. These cells were the only life forms until about 2 billion years ago when (eukaryotic) cells with a nucleus appeared.

Stromatolite
Stromatolite
Archaeozoon acadiense Matthew
Precambrian, Ashburn formation
Saint John, New Brunswick
Collectores: RF Miller 1990;
W Murdoch ca. 1890
(St John Museum, Sept 19 2014)

The most common fossils of the Archaean and Proterozoic Eons are stromatolites, sediment mounds built by cyanobacteria. At 980 million years old, Archaeozoon acadiense is the oldest fossil in New Brunswick. Today stromatolite mounds are rare, found where very salty water limits other organisms from browsing the cyanobacteria. A billion years ago stromatolites were widespread since there were no other organisms to eat them.

Extinction event (大絶滅)


= great extinction, mass extinction, or biotic crisis

(Raup & Sepkoski 1982)

Big Five

1) Ordovician-Silurian extinction event
= End Ordovician (O-S)
70% of species, 57% of genera and 27% of families were extinct
2) Late Devonian extinction
70% of species, 50% of genera and 19% of families were extinct
3) Permian-Triassic extinction event
= End Permian, P/T extinction
90-96% of species, 83% of genera and 57% of families were extinct
4) Triassic-Jurassic extinction event
= End Triassic
48% of genera, 23% of families were extinct (55% of genera and 20% of families in marine)
5) Cretaceous-Paleogene extinction event
= End Cretaceous, K-T extinction, or K-Pg extinction
75% of species, 50% of genera and 17% of families were extinct
6) And now
The present extinction rate is 1000 times faster than the past rate, estimated by fossil record
The future extinction rate is 10 times faster than the present rate
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