Benjamin M. Waggoner

Terrestrial Soft-Bodied Protists and Other Microorganisms in Triassic Amber

Protozoa, cyanobacteria, sheathed algae, sheathed fungi, germinating pollen or spores, and fungal spores have been found in amber 220 to 230 million years old. Many of these microorganisms can be assigned to present-day groups. This discovery of terrestrial, soft-bodied protists that can be referred to modern groups indicates that morphological evolution is very gradual in many protists and that both structural and probably functional stasis extend back at least to the Upper Triassic period.

Fossil microorganisms from Upper Cretaceous amber of Mississippi

Abstract Microfossils are described from Upper Cretaceous amber from Tishomingo County, Mississippi, the first fossils from this amber. They include the oldest fossil record of the chrysomonad Dinobryon and two new actinomycetes, Streptosporangiopsis russelli and Paleomonospora tishomingoensis, the earliest certain fossil representatives of the Streptosporangiaceae and Micromonosporaceae, respectively. Fungal spores and hyphae of uncertain affinities are also reported. The paleoenvironment of these fossils seems to have been aquatic or semi-aquatic. The description of these microfossils is used as a base to establish of these fossils seems to have been aquatic or semi-aquatic. The description of these microfossils is used as a base to establish principles for distinguishing true microfossils from pseudofossils in amber: true microfossils should be completely enclosed inside the amber matrix and should be comparable to living analogues, as far as can be observed, in size and cellular structure.

Unusual oak leaf galls from the middle Miocene of northwestern Nevada

ABSTRAcr-Distinctive galls have been found on a fossil oak leaf from the Miocene Gillam Springs Flora of Washoe County, Nevada. The described galls are located on the leaf surface of Quercus hannibali Dorf, an analogue of the modem species Q. chrysolepis Liebmann. Similar galls are found on extant Quercus, but the fossils seem distinctive enough to warrant description as Antronoides schorni new genus and species. The occurrence of Antronoides schorni coincides with a rapid episode of change from a mesic to a more xeric habitat, with a concomitant shift from an oak-dominated to a conifer-dominated paleoflora. Recent work suggests that speciation and radiation of galling insects is highest in xeric environments, possibly due to decreases in rates of parasitism and disease. This pattern has been documented for modem galling insects and fits the qualitative fossil evidence we present. These galls also support the hypothesis that cynipids in the Antron group originated in Nevada or eastern California and migrated from their point of origin to their current range in the Sierra Nevada and Coast Ranges.

A new chondrophorine (Cnidaria, Hydrozoa) from the cadiz formation (Middle Cambrian) of California

KurzfassungEine neue Chondrophoroidea (Cnidaria, Hydrozoa),Palaelophacmaea valentinei n. sp., wird aus der mittelkambrischen Cadiz-Formation des Marble Gebirges von Kalifornien beschrieben. Dieser Fund dehnt die stratigraphische Reichweite des GenusPalaelophacmaea bis ins frühe Mittel-Kambrium aus und ist bislang der erste aus den westlichen Vereinigten Staaten. Phylogenetische Entwicklungslinien werden anhand einer Übersicht fossiler chondrophoriner Hydrozoen diskutiert.AbstractWe describe a new species of chondrophorine hydrozoan,Palaelophacmaea valentinei sp. nov., from the early Middle Cambrian part of the Cadiz Formation of the Marble Mountains of southeastern California. This find extends the stratigraphic range of this genus into the early Middle Cambrian and its geographic range into the western United States. We review various chondrophorine-like fossils and present a tentative chondrophorine phylogeny in light of this find.

Description and paleoecology of a Triassic amoeba

limbs, were terrestrial cursors, and never ventured up trees. Biophysically, only small reptiles are suited to give rise to birds and hence avian flight via a gliding stage, and it could only be an arboreal or climbing reptile which could represent the stage of proto-gliding or gliding [13, 14]. Arboreal, basal archosaurs occurred during the geologic time period (Triassic) when birds must have originated and were biophysically sized for evolving flight [4, 12], thus offering a clear alternative to dinosaurs as avian progenitors.

Fossil actinomycete in Eocene-Oligocene Dominican amber

Actinomycetes are Gram-positive prokaryotes that tend to form branching and fragmenting filaments, which in some groups form a sizable mycelium. They make up a large and important part of modern terrestrial microfloras but are not known extensively as fossils, although they have a long fossil history. Actinomycete-like fossils appear several times in the Precambrian: in the middle Precambrian Gowganda Formation of Ontario (Jackson, 1967), in the 2.0 Ga Gunflint Chert of Ontario (Lanier, 1987), and possibly in a lichen-like symbiosis in the 2.8 Ga Witwatersrand rocks of South Africa (Hallbauer and Van Warmelo, 1974), among others. Direct fossil evidence of actinomycetes is very rare in the Phanerozoic, and some “fossil” actinomycetes may be later contaminants (Knoll, 1977; Smoot and Taylor, 1983). Hyphae identified as actinomycetes are known from rod-like bodies identified as nematodes inside a decaying scorpion from the lower Carboniferous of Scotland (Stoermer, 1964), and from the interior of fern phloem cells from the Pennsylvanian (Smoot and Taylor, 1983). Unmineralized Actinomyces -like cells are known from calcite in bituminous lake-bed sediments from the early Cretaceous of Nevada (Bradley, 1963), and similar, poorly preserved fossils of a form called Actinomycites have been reported from the Jurassic of Scotland (Ellis, 1915). Actinorhizal nodules, formed by actinomycetes symbiotic with plant roots, have been described from the late Pleistocene (Baker and Miller, 1980).

The ectoparasitic barnacle Anelasma(Cirripedia, Thoracica, Lepadomorpha) on the shark Centroscyllium nigrum (Chondrichthyes, Squalidae) from the Pacific sub-Antarctic

We report the occurrence of the ectoparasitic lepadomorph barnacle Anelasma sp. on the deep-sea squaloid shark Centroscyllium nigrum from the Pacific sub-Antarctic off southern Chile. Anelasma has previously been documented only from the northeast Atlantic on the squaloid shark Etmopterus spinax; this new record extends the known range of Anelasma into the Pacific Ocean and into the Southern Hemisphere, and documents a new host for this parasitic barnacle.

A new hydroid from the Upper Cretaceous of Mississippi

KurzfassungAus Schelfkarbonaten der Prairie Bluff Formation (Maastricht) von Mississippi (Oktibbeha County) wird eine durch Immuration erhaltene, neue Hydroideenart beschrieben. Haftscheibe, Hydrocaulus, Hydranten und Tentakelkränze sind als organischer Abdruck auf der Oberfläche eines Gastropodensteinkerns überliefert und unterscheiden sich morphologisch von allen bislang beschriebenen Arten des Mesozoikums. Die neue Art Mesodendrium oktibbehaensis gen. et sp. nov. wird vorläufig einer noch heute vertretenen Familie zugeordnet (Campanulariidae, Calyptoblastina). Die vollständige Erhaltung von Haftscheibe, Stiel und Kelchen des Hydroiden läßt auf eine sessile Lebensweise innerhalb der Molluskenschale schließen. Von rezenten Hydrozoen mit gleicher Lebensweise ist eine symbiotische Gemeinschaft mit Einsiedlerkrebsen nachgewiesen. Der hier beschriebene Fund läßt erstmals vermuten, daß sich symbiotische Bindungen von Hydrozoen zu Einsiedlerkrebsen bereits in der Oberkreide entwickelt hatten.AbstractA new fossil hydroid is reported as an organic impression on a calcareous gastropod steinkern from the Prairie Bluff Chalk (Maastrichtian), Oktibbeha County, Mississippi. This is the first such hydroid reported from the Upper Cretaceous of the Atlantic Coastal Plain. The fossil organism consists of anastomosing hydrorhizae forming a holdfast, a fascicled hydrocaulus, and elongated, crenulated and ribbed hydrothecae. The fossil is unlike other Mesozoic hydroids that have been reported from Europe and North America; it is described as Mesodendrium oktibbehaensis gen. et sp. nov. and tentiatively referred to an extant family, the Campanulariidae (Calyptoblastina). The complete preservation of the holdfast, hydrocaulus and hydrothecae suggests that this hydroid lived inside gastropod shells. In analogy with Recent symbiotic hydroids inhabiting mollusc shells, the new specimen described here possibly represents the oldest known example of a symbiotic relationship between hydroids and hermit crabs.

Naegleria‐Like Cysts In Cretaceous Amber From Central Kansas

ABSTRACT. Fossil protist cysts are reported from the mid‐Cretaceous amber of Ellsworth County, Kansas, which is rich in terrestrial microfossils but contains no known macrofossils. On the basis of their distinctive morphology, the cysts can be referred to the genus Naegleria (Schizopyrenida); they most closely resemble cysts of the living species Naegleria gruberi. This is the first known fossil record for this group of amoebas. the current phylogenetic position and paleoecological role of Naegleria are discussed in relation to this find; it provides direct confirmation of morphological stasis in this group, which had previously been inferred from rRNA sequence divergence data.,