Abstract Detail

Paleobotany

Contreras, Dori [1], Doyle, James [2], Upchurch, Garland [3].

Implications of fossils for phylogeny and evolution of Cupressaceae sensu lato.

Cupressaceae (including former Taxodiaceae) are arguably the most morphologically diverse modern conifer family and are the only family with a near-global distribution. Cupressaceae have a rich fossil record dating back at least to the Early Jurassic. The ever-growing record of fossil conifers, particularly from the Mesozoic, is greatly expanding known morphological variation, especially in showing character combinations not seen in modern taxa. To date, no phylogenetic analysis has covered both all modern genera of Cupressaceae and a substantial sampling of fossil taxa. Here we present a total evidence analysis of Cupressaceae, including 67 extant species representing all living genera, 56 fossil taxa, and ten outgroup species, using both parsimony and Bayesian methods. The molecular dataset comprises 15 molecular regions from all three genomes, downloaded from GenBank. The morphological dataset consists of 170 characters, representing external and internal traits of foliage, pollen cones, pollen, seed cones, seeds, embryos, and wood, as well as chemical data. Characters were constructed from original observations and the primary literature, with reassessment of characters from earlier clade-specific matrices. In general, we attempted to break down typologies of complex features into substituent characters, and coded characters as contingent where necessary. Morphological data alone recover the major lineages found in molecular analyses, except that either Cupressoideae or Callitroideae are paraphyletic. In both morphological and combined analyses, the addition of fossils to the phylogeny clarifies relationships among extant taxa that were not resolved, particularly among the former Taxodiaceae. Methodological choices, such as the use of quantitative and additive characters, mostly affect resolution within clades and fossil-rich regions of the tree. More notably, inclusion/exclusion experiments with outgroup taxa influence character optimizations at the base of the family and affect the arrangement of fossil taxa that attach near Cunninghamiaand Taiwania, the two earliest-diverging extant lines. All analyses, however, place fossil taxa and clades along the backbone of the family, as well as within the seven extant lineages, resulting in a more complicated picture of the family than can be derived solely from living taxa. In particular, the inclusion of a wide array of fossil taxa provides insight into evolutionary trends in foliage and seed cones that cannot be inferred from living taxa. These analyses provide a new framework for understanding the rich evolutionary history of Cupressaceae, including morphological patterns and diversity dynamics.

1 - University Of California Berkeley, UC Museum Of Paleontology, 1101 Valley Life Sciences, Berkeley, CA, 94720, United States
2 - University Of California Davis, DEPT OF EVOL & ECOLOGY, One Shields Avenue, Davis, CA, 95616, United States
3 - Texas State University, Department Of Biology, 601 University Drive, San Marcos, TX, 78666, United States

Keywords:
Cupressaceae
Conifers
fossils
total evidence phylogeny
Mesozoic.

Presentation Type: Oral Paper
Session: PAL2, Paleobotany II: Paleozoic and Mesozoic Paleobotany
Location: Tucson G/Starr Pass
Date: Monday, July 29th, 2019
Time: 5:00 PM
Number: PAL2006
Abstract ID:1042
Candidate for Awards:None