. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. THE AMMONITE FAMILY BACULITIDAE 51. Fig. 36. Complex suture line of Campanian-Maastrichtian B. ovatus Say, 1821. After Cobban (1974, text-fig. 4). x ORNAMENTATION The following elements of ornamentation can be identified in Baculitidae: 1. Growth lines. In near-smooth, non-ornate forms there are growth lines and striae only. These are often only visible on the shell and absent on internal moulds. Some of the striae may be stronger (lirae) than others. 2. Lateral tubercles—mostly only one row, in
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. THE AMMONITE FAMILY BACULITIDAE 51. Fig. 36. Complex suture line of Campanian-Maastrichtian B. ovatus Say, 1821. After Cobban (1974, text-fig. 4). x ORNAMENTATION The following elements of ornamentation can be identified in Baculitidae: 1. Growth lines. In near-smooth, non-ornate forms there are growth lines and striae only. These are often only visible on the shell and absent on internal moulds. Some of the striae may be stronger (lirae) than others. 2. Lateral tubercles—mostly only one row, in very rare cases two rows connected by ribs of variable strength. The shape, size and spacing of these tubercles varies widely, and they often grade into: 3. Lateral ribs. These can vary from mere transversely elongated tubercles, to distinct, circumperipheral ribs; either single or often bifurcating or with intercalatories on the venter. 4. Ventral corrugations. These are also very variably developed—in some they are mere undulations on the venter, and only present in shelly preservation—in others distinct undulations; also often associated with ventral bifurcating or intercalated ribs. 5. Constrictions. These may appear regularly, and be of taxonomic importance, or random, sometimes as body-chamber modifications only, and of little significance. 6. Ventral tubercles—these are extremely rare. Ornamentation in the early representatives of the family, Lechites and Sciponoceras is very conservative. Lechites has simple, albeit variably spaced, circumperipheral ribbing and occasional constrictions. An aberrant offshoot in. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original South African Museum. Cape Town : The Museum
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
