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(1985), Labandeira and Sepkoski (1993), Farrell (1998), Labandeira (1998), Danforth and Ascher (1999), Grimaldi (1999), Wilf et al. 2009, Specht and Bartlett 2009, Licausi 2011, Glover 2014, among others). Evidence of arthropod-plant interactions in the Upper Triassic of the Southwestern United States. All total in this rich flora of some 6,000 species, there are 812 endemic angiosperms and conifers, 12 endemic genera, and one endemic flowering plant family (A. Distant pinnacles and spires are weathered calc-alkaline Miocene andesites known as the Namosi Volcanics (Rodda and Kroenke 1984). (2008), Specht and Bartlett (2009), Dilcher (2010), D. Isoptera (termites) are hemimetabolous insects (Grimaldi and Engel 2005). The insect developmental tool kit is comprised of certain homeotic selector genes (including Hox genes), zygotic (gap- maternal-, and pair-rule-) genes, field-specific selector genes, compartment selector genes, cell-type-specific selector genes, and segment polarity genes; and the TFs they encode (Rosenberg et al. In addition, the insect developmental tool kit is comprised of controlling factors behind the cessation of insect growth including bioactive PTTH, JH, juvenile hormone esterases, and ecdysone steroids (Truman and Riddiford 2002, Nijhout 2003, S. Juvenile hormone biosynthesized in the corpora allata of the insect brain is a sesquiterpenoid epoxide methyl ester (Hartfelder 2000). Key elements of the Drosophila molecular tool kit include: Evolution of the Hox complex. Ice-free terrestrial environments in the Late Silurian were covered in vegetation. Understanding the origin and diversification of holometabolous insects in deep-time. Caytoniales and angiosperms diverged from a common ancestor with Bennettitales in the Lower Triassic according to Cascales-Miñana et al. Why assume that flowering plants constitute a single clade first appearing 256 MYA without discussing Mathews (2009), Mathews et al. Discerning Fingerprints of Developmental Regulation: This chapter of the essay considers experimental approaches and paleobiological evidence drawn from the research perspective of evo-devo, which is necessary to identify lineages of seed plants involved in the origin and evolution of flowering plants. D., and Mark's help at the delnortea beds is gratefully acknowledged. the [angiosperm] clade probably first appeared during Triassic times," which is a stratigraphically-perplexing Gordian Knot. The preceding statement is quoted from page 399 of David Grimaldi and Michael S. This challenging and daunting approach was facilitated by ready access to several world class research libraries at the University of California, Berkeley. The enigmatic Paleozoic plants Spermopteris and Phasmatocycas reconsidered. (2014), have contributed to our knowledge of the origin and evolution of flowering plants. fossil-based, molecular, phylogenetic and paleobiogeographic studies) and current viewpoints about the explosive Cretaceous diversification of angiosperms. Further, problems associated with co-radiations of angiosperms and insects are brought to light by phylogenetics (T. 2007) suggesting that evolution of certain clades of late Mesozoic phytophagous ants, bees, beetles, butterflies, flies, and moths might be independent of the explosive origin and spread of eudicot orders and families (Labandeira 2014). Root Gorelick (2001) challenges the validity of a biotic coevolutionary hypothesis on the origin of flowering plants. Deciphering the ancestry of flowering plants and their paleoecologies probably requires an understanding of the paleontology of "fingerprints of developmental regulation" (quoted from page 723, Sanders et al. (2006, 2011), Frohlich (2002, 2003, 2006), and Lipeng Zeng et al. "We have examined herein different methodological approaches (i.e. Donoghue (2007), Molecular Palaeobiology, Palaeontology 50(4): 775-804. Presumed co-radiations of flowering plants with chrysomelid beetles are asynchronous (Gómez-Zurita et al. (2014) and Becker (2016), which are determined by expression of CRMs, GRNs, PINs, and TFs. Antiquity of micro RNAs and their targets in land plants. Erbar (2007) summarizes past ideas on a supposed Mesozoic origin of angiosperms from the research perspective of evolutionary-development (evo-devo). Retallack and Dilcher (1981) presented in-depth discussion of Melville's ideas on a glossopterid ancestry of the angiosperms including a reanalysis of glossopterid fructifications. Others suggest that flowering plants evolved from multiple, unrelated seed plant lineages (Edgar Anderson 1934). 2002) and Nair's Triphyletic Theory (Nair 1979) are best placed in this paragraph. Eichler (1976) proposed that unisexual gymnosperms may be the ancestors of angiosperms. Finally the column labeled "Paraphyly or Polyphyly" denotes whether the scientific paper in question attributes the origin of flowering plants to a natural, intergeneric hybridization event, allopolyploidy, or events that brought together two or more distinct lines of seed plant evolution. Doyle and Donoghue 1986, 1987) and classic research by Arber and Parkin (1907), Edgar Anderson (1934), Axelrod (1952), Ehrlich and Raven (1964), Raven and Kyhos (1965), Takhtajan (1969, 1976), and Raven (1977), dovetail with- and potentially support a coevolutionary hypothesis on the origin of flowering plants, which is developed on the following pages of the web site for purposes of classroom and seminar debate and discussion. Doyle 2008) of perianth parts, microsporophylls, and megasporophylls to form a flower was an improbable and unnecessarily complicated saltational event punctuating a long and gradual evolutionary history of angiosperms. Simply put, massive, shortened bisexual cone axes bearing megasporophylls, laminar microsporophylls, and spirally-arranged foliar tepals, probably existed in populations of poorly understood Paleozoic seed plants described as gigantopteroids and Vojnovskyales, groups omitted by J. Doyle and others in their many published phylogenetic analyses. Studies of wood paedomorphosis may offer new clues on a possible Mesozoic origin of angiosperms (Carlquist 2009), but studies of potentially neotenous gymnosperm secondary xylem development in deep (Paleozoic) time are lacking. Additional discussion is available in several papers that reinvestigate conifer cone abnormalities (Flores-Rentería et al. A "No" response (the box is uncolored) indicates that the paper or book chapter in question favors a younger Jurassic or Cretaceous origin of flowering plants.

Taylor and Hickey (1992, 1996), Loconte (1996), and Krassilov (1997, 2002), among others. "The idea is that plants have a plastic and modular developmental system such that simple changes in regulatory genes need not lead to inviability but can generate novel, potentially favored phenotypes." The preceding quotation is from page 83 of D. "Ontogeny in land plants can be viewed as a complex, partly hierarchical, series of developmental processes, which together with their underlying genetic controls, provide the raw material for morphological innovation. The interface between development and ecology may be studied from such perspectives, among others (Enquist et al. "In theoretical morphospaces, the axes of the reduced space are determined by a small set of parameters of morphogenetic or other biological models, derived from theoretical considerations rather than from the organisms themselves" (page 841, Chartier et al. Scaling studies of reproductive short- (spur-) shoots of living Ginkgo are particularly revealing to plant morphologists (Christianson and 2009). Cessation of growth in holometabolous insects leading to a new moulting cycle is triggered by PTTH that initiates the ecdysone growth regulatory cascade.

The image was captured in 1981 while the author was visiting Indiana University. both within and outside the paradigm of transcription-encoding factors ..." (page 129, Niklas 2006). The family Degeneriaceae was discovered in 1942 by I. Endress (1994, 2001 [a book chapter and two papers], 2004), Bateman et al. Several developmental gene families, TFs, and enzymes involved in hormone signaling cascades are known in invertebrates based in part, on experimental studies of the Drosophila model arthropod (S. Wings, halteres, arachnid spinnerets, and insect legs are all organs that develop from limb fields of cells where Ubx expression is prevalent (S. Several insect systematists studying beetle (Coleoptera) evolution are employing some genes and proteins of the insect development tool kit in their phylogenetic analyses (Gómez-Zurita and Galián 2005).

The three essays on the succeeding web pages are written from this research perspective. Gómez-Zurita and Galián (2005) discuss the utility of molecular phylogenetic characters appearing in the entomological literature in a review paper, which is organized along the lines of Floyd and Bowman (2007) for land plants (see section below). Understanding the land plant developmental tool kit and gene regulation from a deep time research perspective ties-in with models of cone and floral organization, cell geometry and regulation of growth from SAMs, paleobiology of homeodomain TF trafficking, phyllotaxis, leaf development, and morphogenesis of fertile organs.

Studies of evolving allometries and body plans might help us understand a possible coevolutionary origin of angiosperms and certain clades of holometabolous phytophagous insect antagonists. Molecular control over arthropod growth varies among the major clades of insects (Grimaldi and Engel 2005).

2007) could potentially be discerned in the fossil record. (2005) review molecular evolution of homeotic genes and homeodomain TFs needed to understand regulation of body ground plan development in phytophagous arthropod antagonists.

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