page_title: Sphecomyrma
section_title: Taxonomy
hierarchical_section_title: Sphecomyrma / Taxonomy
caption_attribution_description: English: Sphecomyrma freyi worker, no. 2, paratype.
context_page_description: Sphecomyrma is an extinct genus of ants which existed in the Cretaceous approximately 79 to 92 million years ago. The first specimens were collected in 1966, found embedded in amber which had been exposed in the cliffs of Cliffwood, New Jersey, by Edmund Frey and his wife. In 1967, zoologists E. O. Wilson, Frank Carpenter and William L. Brown, Jr. published a paper describing and naming Sphecomyrma freyi. They described an ant with a mosaic of features—a mix of characteristics from modern ants and aculeate wasps. It possessed a metapleural gland, a feature unique to ants. Furthermore, it was wingless and had a petiole which was ant-like in form. The mandibles were short and wasp-like with only two teeth, the gaster was constricted, and the middle and hind legs had double tibial spurs. The antennae were, in form, midway between the wasps and ants, having a short first segment but a long flexible funiculus. Two additional species, S. canadensis and S. mesaki, were described in 1985 and 2005, respectively.
  The genus is among the earliest known ants to roam the earth and at the time was considered to be the evolutionary link between ants and wasps.
context_section_description: Before the discovery of the first Sphecomyrma fossils, there were no fossil records of any ants from Cretaceous amber and the oldest social insects at the time extended back to the Eocene epoch; the earliest known ant at the time was described from a forewing found in the Claiborne Formation in Tennessee. The great diversity of ant fossils found in the Baltic amber and Florissant shales of the Oligocene and in the Sicilian amber of the Miocene have prompted entomologists to search for ants of Cretaceous age that may link ants and non-social wasps together. Such a link may shed light on the early origins of ants, but no fossils of any social insect existed before S. freyi was discovered, thus the early evolution of ants remained a mystery. Only a single hymenopterous Upper Cretaceous fossil has been the subject of possible significance to the evolution of aculeate wasps and ants. A single forewing was discovered in Siberia and described in 1957 as Cretavus sibiricus, with the author noting that the wing ventation closely resembles those of bethylid or scoliid wasps, of which these families of wasps have close connections with the origin of ants. However, there were several problems: as the fossil was only a single wing, scientists could not explain or answer whether or not the insect had key diagnostic body traits that would even place it within the subclade Aculeata.
  In 1966, the first fossils of S. freyi were collected by Edmund Frey and his wife during a trip collecting mineralogical specimens in the Magothy exposure near Cliffwood Beach in Raritan Bay, New Jersey. They found a large deep red piece of amber embedded in clay containing a number of insects, including some Diptera flies. The approximate age of the fossils dates back to the Cretaceous, 92 million years ago. Donald Baird of Princeton University first notified Carpenter about the recent discovery, and David Stager of the Newark Museum arranged to transfer the specimens to be studied and examined. At the time, the existence of ants of Cretaceous age was significant, but the ants were most likely not detected as much of the amber around the site was previously collected. The discovery of the ants confirmed the existence of Cretaceous ants, and the appearance of the workers closely matched the speculations of what Mesozoic ants looked like. As a result of these finds, E. O. Wilson and colleagues erected the new subfamily Sphecomyrminae and designated the genus Sphecomyrma (meaning "wasp ant") as the type genus in an article they published in 1967 in the journal Science. The published paper included the first description of S. freyi, which was named after Edmund Frey and his wife. A holotype and a paratype of the species were collected and moved to the Museum of Comparative Zoology, but the holotype was accidentally destroyed. However, a neotype specimen numbered AMNH-NJ-112 was collected from the Sunrise Landing site near Brunswick in 1994, and was subsequently donated to the museum. The holotype was destroyed because the amber was accidentally cracked in half, separating the two workers from each other and later stored in a wooden cabinet in an uncovered drawer with other fossil insects for 30 years; the piece eventually deteriorated, appearing more dark and fractured.
  Although the hypothesised description of what Mesozoic ants looked like was somewhat accurate when compared to actual specimens, some characteristics were inaccurate. They believed that ant-like mandibles first appeared before the development of an ant-like petiole, but such case was proven false when it was opposite on S. freyi specimens (ant-like petiole first appeared before the development of ant-like mandibles). Based on drawings, it was suggested that Mesozoic ants had long mandibles with multiple teeth, toothed tarsal claws and a broadly jointed petiole. Examination of collected specimens, however, shows that these ants had very short mandibles, toothless tarsal claws and a separated petiole.
  S. freyi remained as the sole member of Sphecomyrma until a fossil closely resembling the species
caption: Paratype worker of S. freyi
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