The siphuncle is a strand of tissue passing longitudinally through the shell of a cephalopod mollusk. Only cephalopods with chambered shells have siphuncles, such as the extinct …

…a porous tube called the siphuncle. The chambers contain quantities of water and gas that are adjusted by the siphuncle to achieve neutral buoyancy. Many seashells are brightly coloured in …

The siphuncle in most ammonoids is a narrow tubular structure that runs along the shell's outer rim, known as the venter, connecting the chambers of the phragmocone to the body or living …

The siphuncle is an internal tube that runs through and connects the chambers of the shell. In nautiloids, it runs through the center of the shell chambers, while in almost all planispiral …

2016年10月14日 · Reaching through the interior of the shell is a tubular structure called the siphuncle. The nautilus uses this organ to control the volumes of water and gases within each …

The nature of the siphuncle and its position within the shell are important in classifying nautiloids and can help distinguish them from ammonoids. The siphuncle is on the shell periphery in …

2018年5月8日 · siphuncle A long tube present in those cephalopods (Cephalopoda) that possess external shells. It runs internally, through all the chambers, and contains the siphuncular cord …

2015年8月15日 · The siphuncle is a long and narrow segmented soft tissue that occurs in four extant cephalopods with a phragmocone. It contains blood vessels, connective tissue and …

2015年1月1日 · The siphuncle is a long and narrow segmented soft tissue that occurs in four extant cephalopods with a phragmocone. It contains blood vessels, connective tissue and …

2003年12月1日 · The relative siphuncle surfaces of 250 specimens of the most important clades of shelled cephalopods from the Early Palaeozoic to Cenozoic are compared. An index (si) …