Birds were eaten with seeds 120 million years ago?Misunderstood

Text ｜ "China Science News" reporter Hu Yanqi

Twenty years ago, paleontologists from the Institute of Ancient Poilis and Ancient Human Research Institute (hereinafter referred to as the ancient Human Research Institute of the Chinese Academy of Sciences (hereinafter referred to as the ancient vertebrae) first reported a new kind of primitive bird fossil -primitive hot river birds.

It is the only primitive bird with bone long tail except for the malesbolt.

When the Rehe bird was discovered, there was a special feature, and many plant seed fossils were preserved in its body. Among the middle generation of bird fossils discovered in the past, direct evidence of food nature is rarely found.

Since then, many similar specimens have been published. Therefore, Rehebird has been considered a type of birds living with seeds.

Recently, Dr. Mary Juri, the School of Gejuki, the University of Oxford University, and Zhou Zhonghe, an academician of the Chinese Academy of Sciences, and the researcher at the Institute of Ancient Spine, published a research results on ELIFE.

Their synchronous radiation center of Melbourne in Australia made three -dimensional scanning and reconstruction of the new skulls of the hot river bird, and the skulls and stomach capacity were compared with the gastric capsules and the traversal birds. As a result, Over the past decades, paleontologists have perceived their feeding habits.

Refideliated River Bird. Han Zhixin, Wang Yifan painted

Seed or fruit

There is a seed in the belly of the Rehebird, so it is speculated that it is eaten with seeds. This logic does not seem to be inappropriate.

At the same time, in the case of only qualitative observation, the previous paleontologists also felt that its head looks like a raw bird of eating seeds such as parrots.

The type and method of animal feeding are closely related to the skull form. "However, due to the flattelling storage of fossil specimens and the limitations of traditional research methods, scientists know very little about the skull form of Rehebird." Hu Yan, the first author of the paper, pointed out.

In this new study, researchers used advanced three -dimensional scanning and reconstruction methods to conduct three -dimensional restoration of a hot river bird specimen, obtained morphological information and three -dimensional models for subsequent analysis.

This specimen is collected in the Jiufo Temple formation of Chaoyang, Liaoning, which is about 120 million years old. It preserves a complete head, as well as spine, belt, and some hind limbs, and belongs to the original species of Rehebird.

In addition, the researchers also extracted three -dimensional scanning and reconstruction of existing birds including foods and valleys, including representative species of different food properties, in order to compare ancient and modern.

Hu Yan said that the birds who eat seeds can basically be divided into two types. One uses the beak to open the seeds, and the other is to grind the seeds with gastric stones.

The analysis results show that Rehe bird did not have the high jaw that scientists thought before. Compared with parrots, etc., compared with the cannona that can open seeds, it is obviously different in form, which excludes the possibility of opening seeds to eat.

In order to verify the possibility of another kind of valley — using gastric stone digestion seeds, the researchers performed a gastric capacity analysis.

The results showed that the seedlings of gastric stones digested the seeds still retain the overall form in their belly, but they have different degrees of damage. At the same time, the seeds and gastric stones are mixed with each other and tightly adhered.

In contrast, the seeds preserved in the hot river bird not only lack such damage, but also have more loose preservation, and have never been stored with stomach stones. In this state, it is closer to the state of the seeds in the belly of fruits and birds.

In fact, the hot riverbird and the present fruit birds are not significantly different in the shape of the jaw.

Hu Yan explained that for fruits and birds, it is not necessary to do too much treatment, so it is not surprising that there is no special beak.

At this point, researchers have sufficient evidence that Rehe birds are actually seasonal fruits and birds, and the seeds in the belly are only the products left over from digestion. This is also the earliest fossil record of the ecological habits of bird food.

The earliest plant biography

Many existing birds have special or seasonal fruits habits. They eat plant fruits into their stomachs, hard seeds cannot be completely digested, and they will be discharged from their stools. An important medium to spread plant seeds.

But when this habit appears in the fossil records, it has not been known before.

"The radiation evolution of birds in the early white cymbals is an important event in the evolution of the land ecosystem. It is accompanied by the prosperity and diversity of the plant fruit structure of the entire white -cricket." Hu Yan said that scientists have always guessing early birds in the early days There may be an evolutionary connection with the results of the results, but because the recording of the fossil species is very difficult to determine, this guess has never been proven.

The latest research of this hot river bird shows that in the initial stage of evolution, birds are likely to play the role of plant biography.

Hu Yan believes that, as a propaganda who has a certain range of flying capabilities, the early fruits and birds are likely to assist the expansion of the fruit plants, and the high -quality food of fruit may also expand the evolution of early birds. Sex — the interaction between birds and plants may occupy an important position in the Baiji Period Land Revolution and needs to be further explored.

It is worth mentioning that in this study, the representatives of different foods such as food and valley selected by scientists, including the two "star" species that have only recently extinct, Parrot and travel pigeons.

"In a sense, we are using the recent extinction species to study ancient extinction species." Hu Yan told the China Science News.

Because scientists cannot judge whether the specimen is preserved in the specimen from the outside, it is not realistic to scan each specimen to scan, so the research team's analysis of the gastric container part preferred the specimen samples that have been scanned in Oxford University databases."Compared to other relatively ordinary species, these recent extinction species have a higher probability of scanning, so in the end our data concentration includes these two star species." In Hu Yan, this is also worth our thinking."When humans lose a species, the loss of information may be much more than we think."

Related thesis information:

https://doi.org/10.7554/elife.74751

"China Science News" (2022-09-01 The first edition of the original title is "Eating Seeds? A 20-Year Misunderstanding"))

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