Jacket Gem

46 million years ago, one mosquito, just drunk blood, drowned in a pond and was buried in bottom sediments. There he lay, petrified, until he got into the collection of the National Museum of Natural Sciences of the Smithsonian Institute at the USNM 559050 number. During this time, blood proteins in his stomach collapsed, but hemoglobin, which is associated with oxygen, has been preserved. Having discovered Gem, scientists concluded that insect bloodsuckers existed already 46 million years ago, and there are conditions under which complex organic molecules can be preserved in fossils and, with a successful combination of circumstances, become a material for research.

Luck in such research plays an important role. It is very difficult to determine that an insect found by paleontologists is really a bloodsucker. Diagnosis is based on the structure of the rotary apparatus and belonging to the same systematic group as the current hematophages. There are bloodsuckers in five detachments of modern insects - these are bugs, fleas, some tropical butterflies, but most of all are famous for the vampirism of the two -winged (flies, mosquitoes, mosquitoes, molasses), which includes about 9 thousand types of bloodsuckers belonging to 16 families. Fossil mosquitoes (Culicidae family) are rare. The fact is that most of the finds of the double -winged are insects, stuck in amber, and mosquitoes rarely fly into forests with tarred trees, because they hold closer to the water. Most of the fossil mosquitoes were found in bottom sediments, but such finds are extremely rare. A small light insect that fell on the surface of the water and held by surface tension should also decompose there - if the fish will not eat it even earlier. The chances that it will quickly fall to the bottom and it will immediately drag it with silt, and a tight, blood poured with blood will remain intact, extremely small.

In order to find a USNM 559050 sample, it took an even more amazing combination of circumstances. Dale E. Greenwalt, a cellular cell-to-pension biologist, began to work as a volunteer at the Smithsonian Institute and became interested in messages about the petrified Eocene insects in the Kishenehn ForMation formation in the northwest of Montana. He began to collect samples in these places and met the Constenius family. In the 1980s, the young geologist Kurt Constenius worked on a dissertation and, together with his parents, the norm and Leon collected fossils. Having met Greenwall, the family removed its collection from the basement and transferred to the Smithsonov Institute. It was among these samples that there was a petrified mosquito with blood in the abdomen (never throw anything away!).

Insects are not particularly diverse. They are enclosed in thin records of fuel shale up to 0.25 mm thick - a sediment formed during the season. The fossils themselves are not more than 1-5 mm in length, they can only be seen in a magnifying glass or microscope.

In Eocene, the climate in Montana was tropical and subtropical, Hironomids (non -shifting small midges) swarmed over the lake, which make up almost half of the finds. The second largest water insects are bugs-grains (family Corixidae). Fragments of dragonflies, butterflies and other large insects are rare. Apparently, their bodies rarely reached the bottom intact - fish on the way ate the prey along the way. At the bottom, all drowned people fell into a layer of organic precipitation, which was formed in the summer months, in anaerobic conditions. Researchers managed to find several new species in these deposits, but most are similar to modern insects. As for mosquitoes, 36 samples were removed from the eocene layer, and ten of them are attributed to two new types of genus Culiseta (burning mosquitoes) - CS . Kishenehn and CS . Lemniscata . The discussed sample could not be determined to the view. Looking at the dark, swollen abdomen of USNM 559050, the researchers suspected that the female sawed in front of them. The petrified males were also at their disposal, and scientists compared the samples.

By the method of energy -dispersion X -ray spectroscopy, they determined that a large amount of iron is present in the female abdomen - it is 7.9 times more than in the thoracic part of the body, and 8 times more than in the abdomen of the male (males do not drink blood). These data, as well as the absence in samples of sulfur, indicate that iron entered a mosquito with drunk blood, and not from surrounding rocks. Another method-pastime mass spectrometry of secondary ions (TOF-Sims)-allowed to identify Porfirin molecules in the abdomen. Porphyrin ring with iron ion in the center is a gem, the functional part of hemoglobin, connecting oxygen. Obviously, porphyrins and iron found in the abdomen are the remains of hemoglobin. Whose blood was drank before the death of USNM 559050, researchers do not know.

Porphyrin is often found in fossils, although in most cases it is of plant or microbial origin. However, it is unlikely that mosquito porphyrins are the remains of bacteriochlorophyla or microbial cytochrome. If the sources of Porphyrin were bacteria, their growth would not be limited to an insect's abdomen. Moreover, only anaerobic microbes lived in bottom sediments, in which the level containing porphyrin of cytochromes is very low.

There are very few messages about the finds of hemoglobin and/or hema in petrification, they are not unambiguous and do not tie the find to a certain place. The most famous works of the Paleontologist Mary Schweitzer from the University of North Carolina, which explores blood cells of dinosaurs. She managed to detect traces of hemoglobin in extracts from the spongy bone of dinosaurs Brachylophosaurus canadensis and Tyrannosaurus REX who lived at the end of the Cretaceous period (it should be noted, however, that a number of researchers subjected the work of Schweitzer to doubt, see the TRV-FUCK No. 12 of September 16, 2008.- Note. Ed.). The data of the specialists of the National Museum of Natural Sciences and their colleagues are irrefutably confirmed by the presence of a 46-million long-range hem and make it possible to localize its whereabouts.

According to molecular phylogenetic trees, mosquitoes appeared in the Cretaceous period or, possibly, a little earlier. The oldest copy of the mosquito was found in Burma, in a piece of amber. The insect lived 93.9-100.5 million years ago, in its stomach there were some granules, perhaps blood, but no one examined them. A younger representative of the Cretaceous period (72.1-83.6 million years ago)-male male. Other Mesozoic mosquitoes were not found. There are very few fossils that would directly testify to the hematophagy of the insect. The finds of malaria plasmodium in the salivary glands of the petrified mosquito of the clan are known Cules (some species of this kind tolerate bird malaria); Mosquito with a tripanosoma (originally parasitic unicellular organisms) in the stomach; Faced feces of a bug infected with a tripanosoma. In this case, the researchers managed to get a direct evidence of the existence of blood -sucking mosquitoes in the era of the middle eocene.

These facts make us look at the safety of complex organic molecules in fossils in a new way. Of course, huge fragile DNA molecules could not remain in the geological scale of time, they generally break up very quickly. But with the help of the latest methods such as the pastime mass spectrometry of secondary ions with high resolution and practically do not damage the sample, the researchers were able to detect gem. The petrified drop of blood turned out to be a valuable source of information. Perhaps excavations and examining the existing collections, scientists will find other stable biomolecules. Now they know that searches make sense.

1. Greenwalt de, Goreva Ys, Siljestrom Sm, Rose T, Harbach Re (2013) Hemoglobin-Derved Porphyrins Preserved in a Middle Eocene Bloodengorged Mosquito. ProC Natl Acad Sci USA 110: 18496-18500
2. Briggs Deg (2013) A Mosquito's Last Supper Reminds us Not to Underestimate the Fossil Record. ProC Natl Acad Sci USA 110: 18353-18354
3. Jurassic Park: Is the opening postponing? TRV-hunger No. 12, September 16, 2008
4. Interview with Pavel Pevzner. TRV-hunger No. 12, September 16, 2008