A Microbiological Examination of Some Carbonaceous Chondrites

Bacterial morphologies supporting cometary panspermia: a reappraisal

“…An intriguing controversy followed reports by Claus and Nagy (1961) and Urey (1966) in which it was claimed that microbial fossils are present in several carbonaceous chondrites. Although electron micrographs revealed evidence of structures resembling cell walls and flagellae and a wide range of biological morphologies, all these identifications came to be discredited because contamination by ragweed pollen was demonstrated in at least one instance.…”

Biology and the Exploration of Mars

“…This observation was followed by work by Claus and Nagy [1961] and by Nagy, Claus and Hennessy [1962] in which they described microscopic particles from Orgueil and I vuna, both Type 1 carbonaceous chondrites. They suggested that these were microfossils.…”

“…discussion]. Structured inclusions superficially resembling microorganisms have been found in carbonaceous chondrites [Claus and Nagy, 1961;Claus, Nagy, and Europa, 1963]; but some of these have been shown to result from terrestrial biological contamination -for example, by ragweed pollen [Fitch and Anders, 1963a, b]. It is not now known whether there is a remaining category of such highly structured and symmetrical forms in the 10,.. size range, composed of organic material (or a likely fossil replacement), that can be shown not to be terrestrial contaminants.…”

Microfossil-like objects in meteorites

“…ORGANIZED ELEMENTS CLAUS and NAGY (1961) observed five types of organized elements. Four of these resemble species of terrestrial dinoflagellates or chrysomonads which live only i Postal address: Cortezlaan 9, Utrecht (The Netherlands).…”

“…All of these were observed falling. After several investigators had shown chemically that these chondrites contain organic matter, such as fatty acids, hydrocarbons, vanadyl porphyrins and optically active lipids, CLAUS and NAGY (1961) reported that they had found, embedded in the Orgueil and the lvuna meteorites, so-called "organized elements", which probably are microscopic-sized organic particles, morphologically resembling unicellular microfossils. It is interesting to note that there is general agreement among meteorite investigators, that the meteorite parent body contained water and had a low-temperature history.…”