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Baltisphaeridium pattei
Baltisphaeridium pattei, (Valensi, 1949), Sarjeant, 1960
Now Pandadinium. Originally Hystrichosphaeridium, subsequently Baltisphaeridium, thirdly Lanterna fourthly Lanterna?, fifthly (and now) Pandadinium.
Holotype: Valensi, 1949, fig.1
Age: Bathonian
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Original description: [Valensi, 1949, p. 539-540] (translated from French):
Holotype: Lower Bathonian, flint from Airvault (Deux-Sèvres).
The shell is large and globular in shape, it bears numerous very short processes, extremely dense, and tightly packed together to the point of constituting a veritable forest; its surface is covered with a network very characteristic of the species, with roughly polygonal meshes and sinuous outline; the processes are inserted into this network as well at the nodes as at any other point; they are hollow, not widened at their base and generally straight, their width remains constant from the base to the top, and their extremity is capped with two small perpendicular lobes, straight, or more or less arched; other processes take the form of straight or curved spines.
In the holotype (fig. 1) the largest diameter of the shell is 37 μ, the smallest 34 μ, the processes are 3 μ long which gives a total diameter ranging from 40 to 43 μ. The color of all the specimens observed is dark brown.
I found some debris of this species in other flints from the Lower Bathonian of Airvault and a slightly damaged, but very clear specimen at the base of the Bathonian of the Mouchedune farm near Saint-Benoît (Vienne); ovoid in shape, with a large end and a small end, it shows the same polygonal network, but the processes are both longer (4 to 5 μ) and wider, the shell is of smaller dimensions (32 μ by 28 μ) without the processes and contains a small red nodule, which is quite common.
Individuals of intermediate size have been found in the Lower Bathonian of Mouchedune and Moulinet.
So far I have not encountered this species in the Middle Jurassic of Normandy, and no exactly similar form has been described in the Cretaceous or the Silurian. However, this morphological type, characterized by numerous short forked processes, is already represented in these stages by collective species such as Hystrichosphaeridium multifurcatum Defl. (from the Cretaceous) and Hystrichosphaeridium hystricho-reticulatum Eisenack (from the Silurian).
Now Pandadinium. Originally Hystrichosphaeridium, subsequently Baltisphaeridium, thirdly Lanterna fourthly Lanterna?, fifthly (and now) Pandadinium.
Holotype: Valensi, 1949, fig.1
Age: Bathonian
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Valensi, 1949, p. 539-540] (translated from French):
Holotype: Lower Bathonian, flint from Airvault (Deux-Sèvres).
The shell is large and globular in shape, it bears numerous very short processes, extremely dense, and tightly packed together to the point of constituting a veritable forest; its surface is covered with a network very characteristic of the species, with roughly polygonal meshes and sinuous outline; the processes are inserted into this network as well at the nodes as at any other point; they are hollow, not widened at their base and generally straight, their width remains constant from the base to the top, and their extremity is capped with two small perpendicular lobes, straight, or more or less arched; other processes take the form of straight or curved spines.
In the holotype (fig. 1) the largest diameter of the shell is 37 μ, the smallest 34 μ, the processes are 3 μ long which gives a total diameter ranging from 40 to 43 μ. The color of all the specimens observed is dark brown.
I found some debris of this species in other flints from the Lower Bathonian of Airvault and a slightly damaged, but very clear specimen at the base of the Bathonian of the Mouchedune farm near Saint-Benoît (Vienne); ovoid in shape, with a large end and a small end, it shows the same polygonal network, but the processes are both longer (4 to 5 μ) and wider, the shell is of smaller dimensions (32 μ by 28 μ) without the processes and contains a small red nodule, which is quite common.
Individuals of intermediate size have been found in the Lower Bathonian of Mouchedune and Moulinet.
So far I have not encountered this species in the Middle Jurassic of Normandy, and no exactly similar form has been described in the Cretaceous or the Silurian. However, this morphological type, characterized by numerous short forked processes, is already represented in these stages by collective species such as Hystrichosphaeridium multifurcatum Defl. (from the Cretaceous) and Hystrichosphaeridium hystricho-reticulatum Eisenack (from the Silurian).