Programa de Pós-Graduação em Biologia Comparada, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, 14040- 901, Brazil.
Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, 14040-901, Brazil.
Naturwissenschaften. 2022 Nov 4;109(6):55. doi: 10.1007/s00114-022-01824-7.
All known species of the Triassic archosauromorph genus Tanystropheus are known to have had the longest neck in proportion to their torso. This feature is related to a series of ventilatory challenges since an increase in neck length also increases airway length and, therefore, the volume of stagnant air that does not reach the lungs, the dead space volume. Based on this challenge, the objective of the present study was to model the type of respiratory system of Tanystropheus able to meet its metabolic demands during the early Triassic period. The modeling was based on allometric relations for morphological and physiological ventilatory and metabolic variables, and to do so, the mean body mass of Tanystropheus was estimated based on three different methods. In addition, the tracheal airflow was also estimated based on the proportions of Tanystropheus elongated neck, the results of allometric modeling, and fundamental equations of fluid mechanics. The estimation of the body mass indicated that an animal of 3.6 m would possess a body mass of 50.6 ± 21.6 kg. Allometric modeling suggested that the respiratory system best suited to Tanystropheus' oxygen demands, especially during activity, would be a generic reptilian-like respiratory system composed of multicameral lungs. The best respiratory pattern to maintain adequate tracheal flow rates and effective pulmonary ventilation would be one ventilating the relatively narrower trachea at lower frequencies to deal with tracheal dead space volume.
所有已知的三叠纪槽齿目恐龙属 Tanystropheus 物种都以其身体比例最长的颈部而闻名。这一特征与一系列通气挑战有关，因为颈部长度的增加也会增加气道长度，从而增加无法到达肺部的停滞空气量，即死腔量。基于这一挑战，本研究的目的是为 Tanystropheus 建立一种呼吸系统模型，以满足其在早三叠世的代谢需求。该模型基于形态学和生理学通气和代谢变量的异速关系，为此，根据三种不同的方法估计了 Tanystropheus 的平均体重。此外，还根据 Tanystropheus 伸长的颈部比例、异速模型的结果以及流体力学的基本方程来估计气管气流。体重估计表明，3.6 米长的动物的体重将为 50.6 ± 21.6 公斤。异速模型表明，最适合 Tanystropheus 氧气需求的呼吸系统，特别是在活动期间，将是一种由多腔肺组成的通用似爬行动物呼吸系统。保持适当的气管流量和有效肺通气的最佳呼吸模式将是一种以较低频率通气相对较窄气管的模式，以应对气管死腔量。
