All statistics are based on contigs of size >= 500 bp, unless otherwise noted (e.g., "# contigs (>= 0 bp)" and "Total length (>= 0 bp)" include all contigs).
Suggestion: assemblies supernova_pseudohap_duck4-p, 20180421_Hi-C contain continuous fragments of N's of length >= 10 bp. You may consider rerunning QUAST using --scaffolds (-s) option!

Assembly                    20180405_sparse_kmer101  supernova_pseudohap_duck4-p  20180421_Hi-C
# contigs (>= 0 bp)         24683708                 315013                       313624       
# contigs (>= 1000 bp)      383849                   315013                       313624       
# contigs (>= 5000 bp)      18465                    50433                        49052        
# contigs (>= 10000 bp)     3320                     15361                        13989        
# contigs (>= 25000 bp)     139                      3350                         2002         
# contigs (>= 50000 bp)     4                        1541                         225          
Total length (>= 0 bp)      4517188232               2205550088                   2205690788   
Total length (>= 1000 bp)   789016315                2205550088                   2205690788   
Total length (>= 5000 bp)   148019238                1634904607                   1635063665   
Total length (>= 10000 bp)  47110700                 1397407710                   1397630676   
Total length (>= 25000 bp)  4342838                  1225188922                   1225799503   
Total length (>= 50000 bp)  222433                   1164206709                   1166189936   
# contigs                   1158269                  315013                       313624       
Largest contig              65191                    13378076                     95480635     
Total length                1315630106               2205550088                   2205690788   
GC (%)                      33.99                    33.92                        33.92        
N50                         1241                     177022                       43382739     
N75                         750                      4745                         4746         
L50                         265572                   834                          18           
L75                         613735                   54388                        52996        
# N's per 100 kbp           0.00                     9137.01                      9142.81