66 R. Rößler / Review of Palaeobot<strong>an</strong>y <strong>an</strong>d Palynology 108 (2000) 55–74 PLATE V
R. Rößler / Review of Palaeobot<strong>an</strong>y <strong>an</strong>d Palynology 108 (2000) 55–74 permineralized Callistophyton pl<strong>an</strong>t remains from cells <strong>an</strong>d thin-walled cells of the ?periderm the Lower Permi<strong>an</strong> age pyroclastics of Chemnitz. (P<strong>late</strong> VI, 5). Additionally, figured material Several fragments of silicified <strong>Psaronius</strong> root m<strong>an</strong>- (P<strong>late</strong> VI, 5) shows coprolites enriched within the tles allowed the recognition of Callistophyton-like phloem tissue of the Callistophyton roots. pl<strong>an</strong>t fragments. <strong>The</strong> material exclusively consists Compression material of Dicksonites pluckenetii of roots. (Schlotheim) Sterzel that is suggested to be closely In a fragment of the largest known <strong>Psaronius</strong> re<strong>late</strong>d to Callistophytales (Stidd <strong>an</strong>d Barthel, trunk (MfNC K 620), Stenzel (unpubl.) found a 1979; Meyen <strong>an</strong>d Lemoigne, 1986) is also noted curious ‘<strong>Psaronius</strong> root’ showing secondary xylem. from the Zeisigwald tuff horizon of Chemnitz. Butterworth (1900) <strong>an</strong>d Scott (1900: p. 275) Besides, regarding the growth habit of the pl<strong>an</strong>t described comparable features on <strong>Psaronius</strong> cromp- there exists a close relationship between the recon- tonensis from the Coal Measures of L<strong>an</strong>cashire. struction given by Rothwell (1975), <strong>an</strong>d Permi<strong>an</strong> Finally, Solms-Laubach (1911) dealt with that compression material of the Saar-Nahe Basin, phenomenon, <strong>an</strong>d he re-examined thin sections of Germ<strong>an</strong>y, figured by Barthel (1996: fig. 8). In the Butterworth’s <strong>an</strong>d Scott’s material. Moreover, he light of the new finds presented here, which show mentioned comparable observations on <strong>Psaronius</strong> Callistophyton org<strong>an</strong>s growing on <strong>Psaronius</strong> specimens from Brasil (coll. Solms 581, 582, 588). trunks, the observation of Zeiller (1888, pl. VIII, However, he did not recognize the true nature of fig. 1) regarding the doubtful connection of the small roots. <strong>The</strong> Chemnitz specimen mentioned <strong>Psaronius</strong> stems <strong>an</strong>d D. sterzeli fronds becomes by Solms-Laubach (1911) was re-examined, observations based on new finds were added, <strong>an</strong>d both clearer, <strong>an</strong>d may be regarded as solved now. lines of evidence support the interpretation <strong>an</strong>d identification as roots of Callistophyton. Moreover, 3.3. <strong>Psaronius</strong> <strong>an</strong>d evidence of <strong>an</strong>imal life the Chemnitz material exhibits different sizes of As several authors recently showed, different the roots from thin rootlets (P<strong>late</strong> VI, 6, 7 to arthropods play <strong>an</strong> import<strong>an</strong>t role in Permo- relatively thick ones (P<strong>late</strong> VI, 1–5). As Rothwell Carboniferous <strong>ecosystem</strong>s (Todd, 1991; Dunlop, (1975) has shown, Callistophyton roots are proto- 1994; Lab<strong>an</strong>deira et al., 1997). <strong>The</strong> frequent presstelic <strong>an</strong>d diarch, with exarch maturation of the ence of numerous predators, such as trigonotarbids primary xylem. <strong>The</strong> smaller ones measure 0.5– <strong>an</strong>d phal<strong>an</strong>giotarbids suggests highly developed 0.9 mm in diameter, <strong>an</strong>d consist of a diarch pri- food webs. Representatives of the lowest level may mary xylem surrounded by a continuous zone of be some detritivores or herbivores such as mites, primary cortex. Some of the isodiametric cells of collembol<strong>an</strong> hexapods or isopods that played <strong>an</strong> the cortex contain dark contents. <strong>The</strong> outermost import<strong>an</strong>t role in decomposing pl<strong>an</strong>t litter (Scott, slightly darker cell layer may represent the rhizo- 1977). M<strong>an</strong>y arthropod groups produce faecal dermis. <strong>The</strong> larger mature roots measure 5.2– pellets of distinctive sizes that may be fossilized. 6.4 mm in diameter, <strong>an</strong>d exhibit m<strong>an</strong>y radial rows <strong>The</strong>refore, coprolites of different size, shapes <strong>an</strong>d of secondary xylem. Vascular cambium <strong>an</strong>d contents are very abund<strong>an</strong>t in the fossil record. secondary phloem surround the xylem. <strong>The</strong> Nevertheless, faecal pellets of most fossil arthro- phloem is surrounded by a few layers of cortical pod groups are less well known. PLATE V 1. Portion from the outer root zone of a <strong>Psaronius</strong> trunk containing two Tubicaulis sp. specimens (white arrows), two Anachoropteris pulchra petioles (small black arrows) <strong>an</strong>d one ?Grammatopteris sp. axis (big black arrow), MMG SaP 1900. 2. Detail of 1, iso<strong>late</strong>d Anachoropteris pulchra petiole, ×10. 3. Detail of 1, iso<strong>late</strong>d Anachoropteris pulchra petiole, ×12. 4. Protostele <strong>an</strong>d leaf traces of Grammatopterus baldaufii (Beck) Hirmer from Chemnitz for comparison with 5, BAF 171/1, ×6. 5. Detail of 1, ?Grammatopteris sp. axis, ×6. 67