What is the inner nostril, explanation of the inner nostril

The closest fish to the tetrapod is the flesh-finned fish, with only four genera of living species (the African lungfish, the South American lungfish, the Australian lungfish and the "living fossil" Latimai fish). Scientists have shown that lungfish, like other fish, do not have a true inner nostril, only two outer nostrils, anterior and posterior. To ** the origin of the inner nostrils, evidence must be found in fossils.

One view is that the inner nostrils evolved from the outer nostrils; Another view is that the inner nostrils are nascent structures.

In the 30s of the last century, Professor Järvik, a famous Swedish paleontologist, believed that the internal nostrils were a new structure of tetrapods, and there was no connection between the inner nostrils and the outer nostrils. They believe that during the evolution of fish, one pair of nostrils gradually disappeared, and then a new pair of inner nostrils appeared.

The evidence they hold is that they were found in the fossils of foramen fishes that not only had a pair of internal nostrils, but also two outer nostrils. This is known as the "three-hole theory".

At the same time, some scholars have put forward another view: the inner nostrils of fish evolved from one pair of nostrils, and the most difficult to explain is the "three pairs of nostrils" in the fossil foramen scale fish. Due to the lack of strong fossil evidence, this view was not widely supported at the time, and the question of the origin of the inner nostrils became an open question.

All quadrupeds, including humans, rely on their lungs to breathe, so they must have an inner nostril that communicates with the outer nostrils, so that the outside air can enter the lungs smoothly and ensure the animal's oxygen needs. The inner nostrils form a passage between the nasal cavity and the mouth, so that we can breathe as usual when we eat and sleep. The internal nostrils are one of the important features of tetrapods adapted to life on land, but the process of its origin has been a matter of debate in the academic community.

In the early 80s, China's famous paleontologist Academician Zhang Miman discovered a fossil of a flesh-fin fish——— Yang's fish, which has many similarities with foramen scale fish. This work has once again drawn academic attention to the question of the origin of the internal nostrils.

According to the traditional view, Yang's fish should also have internal nostrils, but after a careful study of Yang's snout, Academician Zhang Miman found that "Yang's fish only has two external nostrils, and the inner nostrils that were thought to exist in the past do not exist at all". This discovery immediately aroused heated discussions and reflections among scientists at home and abroad. Studies have shown that in fish with two outer nostrils, such as foramen scales, the so-called "inner nostrils" do not exist.

This unravels a puzzle for the doctrine that the inner nostrils originate from the outer nostrils.

Although the "three-hole" theory was rejected, the research at the time still did not answer the question of the origin of the internal nostrils. All the external nostrils form a jaw arch at the anterior maxilla, with the outer nostrils outside the mandibular arch and the inner nostrils inside the jaw arch.

Chinese scientists have found fish fossils and confirmed that the inner nostrils are indeed formed by the "drift" of the outer nostrils.

In the early 90s, in the "hometown of fish", Academician Zhang and Dr. Zhu Min discovered another ancient fish fossil. It lived hundreds of millions of years ago and is the most primitive quadruped animal, which is the Ken's fish. Fish older than Kent's fish, with two pairs of nostrils; The fish, which are more advanced than the Ken's fish, have become an outer nostril and a pair of inner nostrils, so that the position of the Ken's fish has become the key to the evolution of the nostrils.

However, due to the limitations of fossil materials at the time, the preliminary study of Kent's fish did not have any special results.

Since 2000, Dr. Zhu Min has led several consecutive excavations in the field and discovered a large number of new fossils. Through meticulous taxidermy repair and research, they have made important progress in the study of Ken's fish. This time, they were fortunate to find that the Kent's fish was in the transition from the outer nostril to the inner nostril.

It has been difficult to explain in the past, how the outer nostril "drifts" from the lateral side of the head to the inside to form the inner nostril? How do they cross the jaw arch between the maxilla and the anterior maxilla in fish? Interestingly, the position of the inner nostril of the Ken's fish is exactly at the position of the "drift" of the outer nostril to the inner nostril, and the drift is exactly when the anterior maxilla and maxilla are split, and there is a tear between them, which is the position of the inner nostril of the Ken's fish, and the stage of the dehiscence is exactly in line with this drift characteristic.

This is a fossil evidence.

This means that in the evolution of flesh-finned fishes, there was a process in which the maxilla and anterior maxilla split and then rejoined, which provided a channel for the "drift" of the nostrils. Kent's fish provides empirical evidence for this explanation and establishes a homology relationship between the inner and posterior lateral nostrils.

Very similar to this principle, in the early stage of embryonic development, there will be a gap in the same position of the palate, and the normal fetus will close in the later stage of development.

Interpretation of the nostrils [naris; nostril]

the outer opening of the nose; Refers to the anterior part of the nasal fossa with an external opening in the nose Explain in detail The orifice between the nasal cavity and the outside. "The Legend of the Teacher": The nostrils are outside, and the bladder is leaking.

Song Wen Tianxiang's poem "Mei": "I thought that the fragrance was not fragrant, and the nostrils were suffocated." "The Strange Status Quo Witnessed in Twenty Years" Chapter 13:

The old woman asked for a rooster to come and pour some chicken blood into her mouth, and then she slowly felt a little angry in her nostrils. Mao Dun's "Color Blindness" I: "In the shock of the car moving forward, Lin Baishuang's shoulder touched something warm and soft, and at the same time, an intoxicating fragrance penetrated his nostrils.

Word Breakdown Explanation of the nose Nose í olfactory organ, which is also the orifice of breathing: the nose. Sinus.

Nostril. Nasal cavity. Snot.

Rhinolalia. Snuff (powdered smoke inhaled through the nostrils). Snort.

Sneer at. radical : nose; Kong Qixun's explanation Kong Xiang let ǒ small hole, hole :

Cavity. Holes. Holes.

Brother Kong Fang (referring to money, because the old copper coins have square holes, which are harmonious and contemptible). Very: Urgent.

Kong Wu is powerful. Measure word, used for cave: a hole in an earthen kiln.

Surname. Radical: Sub.